Java文件操作大全

1.创建文件夹  
File myFolderPath = new File(%%1);  
try {  
if (!myFolderPath.exists()) {  
     myFolderPath.mkdir();  
}  
}  
catch (Exception e) {  
System.out.println("新建目录操作出错");  
e.printStackTrace();  
}   
 
2.创建文件  
File myFilePath = new File(%%1);  
try {  
if (!myFilePath.exists()) {  
myFilePath.createNewFile();  
}  
FileWriter resultFile = new FileWriter(myFilePath);  
PrintWriter myFile = new PrintWriter(resultFile);  
myFile.println(%%2);  
resultFile.close();  
}  
catch (Exception e) {  
System.out.println("新建文件操作出错");  
e.printStackTrace();  
}   
 
3.删除文件  
File myDelFile = new File(%%1);  
try {  
myDelFile.delete();  
}  
catch (Exception e) {  
System.out.println("删除文件操作出错");  
e.printStackTrace();  
}   
 
4.删除文件夹  
File delFolderPath = new File(%%1);  
try {  
delFolderPath.delete(); //删除空文件夹  
}  
catch (Exception e) {  
System.out.println("删除文件夹操作出错");  
e.printStackTrace();  
}   
 
5.删除一个文件下夹所有的文件夹  
File delfile=new File(%%1);  
File[] files=delfile.listFiles();  
for(int i=0;i<files.length;i++){  
if(files[i].isDirectory()){  
files[i].delete();  
    }  
}   
 
6.清空文件夹  
File delfilefolder=new File(%%1);  
try {  
if (!delfilefolder.exists()) {  
delfilefolder.delete();  
}  
delfilefolder.mkdir();  
}  
catch (Exception e) {  
System.out.println("清空目录操作出错");  
e.printStackTrace();  
}   
 
7.读取文件  
// 逐行读取数据  
FileReader fr = new FileReader(%%1);  
BufferedReader br = new BufferedReader(fr);  
String %%2 = br.readLine();  
while (%%2 != null) {  
%%3 
%%2 = br.readLine();  
}  
br.close();  
fr.close();   
 
8.写入文件  
// 将数据写入文件  
FileWriter fw = new FileWriter(%%1);  
fw.write(%%2);  
fw.close();   
 
9.写入随机文件  
try {  
RandomAcessFile logFile=new RandomAcessFile(%%1,"rw");  
long lg=logFile.length();  
logFile.seek(%%2);  
logFile.writeByte(%%3);  
}catch(IOException ioe){  
System.out.println("无法写入文件："+ioe.getMessage());  
}   
 
10.读取文件属性  
// 文件属性的取得  
File af = new File(%%1);  
if (af.exists()) {  
System.out.println(f.getName() + "的属性如下： 文件长度为：" + f.length());  
System.out.println(f.isFile() ? "是文件" : "不是文件");  
System.out.println(f.isDirectory() ? "是目录" : "不是目录");  
System.out.println(f.canRead() ? "可读取" : "不");  
System.out.println(f.canWrite() ? "是隐藏文件" : "");  
System.out.println("文件夹的最后修改日期为：" + new Date(f.lastModified()));  
} else {  
System.out.println(f.getName() + "的属性如下：");  
System.out.println(f.isFile() ? "是文件" : "不是文件");  
System.out.println(f.isDirectory() ? "是目录" : "不是目录");  
System.out.println(f.canRead() ? "可读取" : "不");  
System.out.println(f.canWrite() ? "是隐藏文件" : "");  
System.out.println("文件的最后修改日期为：" + new Date(f.lastModified()));  
}  
if(f.canRead()){  
%%2 
}  
if(f.canWrite()){  
%%3 
}   
 
11.写入属性  
File filereadonly=new File(%%1);  
try {  
boolean b=filereadonly.setReadOnly();  
}  
catch (Exception e) {  
System.out.println("拒绝写访问："+e.printStackTrace());  
}   
 
12.枚举一个文件夹中的所有文件夹   
 
//import java.io.*;  
//import java.util.*;  
ArrayList<String> folderList = new ArrayList<String>();  
folderList.add(%%1);  
for (int j = 0; j < folderList.size(); j++) {  
File file = new File(folderList.get(j));  
File[] files = file.listFiles();  
ArrayList<File> fileList = new ArrayList<File>();  
for (int i = 0; i < files.length; i++) {  
if (files[i].isDirectory()) {  
folderList.add(files[i].getPath());  
} else {  
fileList.add(files[i]);  
}  
}  
for (File f : fileList) {  
%%2=f.toString();  
%%3 
}  
}   
 
13.复制文件夹   
//import java.io.*;  
//import java.util.*;  
ArrayList<String>folderList=new ArrayList<String>();  
folderList.add(%%1);  
ArrayList<String>folderList2=new ArrayList<String>();  
folderList2.add(%%2);  
for(int j=0;j<folderList.length;j++){  
    (new File(folderList2[j])).mkdirs(); //如果文件夹不存在 则建立新文件夹  
    File folders=new File(folderList[j]);  
    String[] file=folders.list();  
    File temp=null;  
    try {  
      for (int i = 0; i < file.length; i++) {  
        if(folderList[j].endsWith(File.separator)){  
          temp=new File(folderList[j]+"/"+file[i]);  
        }  
        else{  
          temp=new File(folderList[j]+"/"+File.separator+file[i]);  
        }  
          FileInputStream input = new FileInputStream(temp);  
        if(temp.isFile()){  
          FileInputStream input = new FileInputStream(temp);  
          FileOutputStream output = new FileOutputStream(folderList2[j] + "/" +  
              (temp.getName()).toString());  
          byte[] b = new byte[5120];  
          int len;  
          while ( (len = input.read(b)) != -1) {  
            output.write(b, 0, len);  
          }  
          output.flush();  
          output.close();  
          input.close();  
        }  
        if(temp.isDirectory()){//如果是子文件夹  
          folderList.add(folderList[j]+"/"+file[i]);  
          folderList2.add(folderList2[j]+"/"+file[i]);  
        }  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制整个文件夹内容操作出错");  
      e.printStackTrace();  
    }  
}   
 
14.复制一个文件夹下所有的文件夹到另一个文件夹下  
File copyfolders=new File(%%1);  
File[] copyfoldersList=copyfolders.listFiles();  
for(int k=0;k<copyfoldersList.length;k++){  
if(copyfoldersList[k].isDirectory()){  
ArrayList<String>folderList=new ArrayList<String>();  
folderList.add(copyfoldersList[k].getPath());  
ArrayList<String>folderList2=new ArrayList<String>();  
folderList2.add(%%2+"/"+copyfoldersList[k].getName());  
for(int j=0;j<folderList.length;j++){  
    (new File(folderList2[j])).mkdirs(); //如果文件夹不存在 则建立新文件夹  
    File folders=new File(folderList[j]);  
    String[] file=folders.list();  
    File temp=null;  
    try {  
      for (int i = 0; i < file.length; i++) {  
        if(folderList[j].endsWith(File.separator)){  
          temp=new File(folderList[j]+"/"+file[i]);  
        }  
        else{  
          temp=new File(folderList[j]+"/"+File.separator+file[i]);  
        }  
          FileInputStream input = new FileInputStream(temp);  
        if(temp.isFile()){  
          FileInputStream input = new FileInputStream(temp);  
          FileOutputStream output = new FileOutputStream(folderList2[j] + "/" +  
              (temp.getName()).toString());  
          byte[] b = new byte[5120];  
          int len;  
          while ( (len = input.read(b)) != -1) {  
            output.write(b, 0, len);  
          }  
          output.flush();  
          output.close();  
          input.close();  
        }  
        if(temp.isDirectory()){//如果是子文件夹  
          folderList.add(folderList[j]+"/"+file[i]);  
          folderList2.add(folderList2[j]+"/"+file[i]);  
        }  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制整个文件夹内容操作出错");  
      e.printStackTrace();  
    }  
}  
}  
}   
 
15.移动文件夹  
ArrayList<String>folderList=new ArrayList<String>();  
folderList.add(%%1);  
ArrayList<String>folderList2=new ArrayList<String>();  
folderList2.add(%%2);  
for(int j=0;j<folderList.length;j++){  
    (new File(folderList2[j])).mkdirs(); //如果文件夹不存在 则建立新文件夹  
    File folders=new File(folderList[j]);  
    String[] file=folders.list();  
    File temp=null;  
    try {  
      for (int i = 0; i < file.length; i++) {  
        if(folderList[j].endsWith(File.separator)){  
          temp=new File(folderList[j]+"/"+file[i]);  
        }  
        else{  
          temp=new File(folderList[j]+"/"+File.separator+file[i]);  
        }  
          FileInputStream input = new FileInputStream(temp);  
        if(temp.isFile()){  
          FileInputStream input = new FileInputStream(temp);  
          FileOutputStream output = new FileOutputStream(folderList2[j] + "/" +  
              (temp.getName()).toString());  
          byte[] b = new byte[5120];  
          int len;  
          while ( (len = input.read(b)) != -1) {  
            output.write(b, 0, len);  
          }  
          output.flush();  
          output.close();  
          input.close();  
        }  
        if(temp.isDirectory()){//如果是子文件夹  
          folderList.add(folderList[j]+"/"+file[i]);  
          folderList2.add(folderList2[j]+"/"+file[i]);  
        }  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制整个文件夹内容操作出错");  
      e.printStackTrace();  
    }  
}  
File movefile=new File(%%1);  
File[] movefiles=movefile.listFiles();  
for(int i=0;i<files.length;i++){  
if(files[i].isDirectory()){  
files[i].delete();  
    }  
}  
movefile.delete();  
 
16.移动一个文件夹下所有的文件夹到另一个目录下  
File movefolders=new File(%%1);  
File[] movefoldersList=movefolders.listFiles();  
for(int k=0;k<movefoldersList.length;k++){  
if(movefoldersList[k].isDirectory()){  
ArrayList<String>folderList=new ArrayList<String>();  
folderList.add(movefoldersList[k].getPath());  
ArrayList<String>folderList2=new ArrayList<String>();  
folderList2.add(%%2+"/"+movefoldersList[k].getName());  
for(int j=0;j<folderList.length;j++){  
    (new File(folderList2[j])).mkdirs(); //如果文件夹不存在 则建立新文件夹  
    File folders=new File(folderList[j]);  
    String[] file=folders.list();  
    File temp=null;  
    try {  
      for (int i = 0; i < file.length; i++) {  
        if(folderList[j].endsWith(File.separator)){  
          temp=new File(folderList[j]+"/"+file[i]);  
        }  
        else{  
          temp=new File(folderList[j]+"/"+File.separator+file[i]);  
        }  
          FileInputStream input = new FileInputStream(temp);  
        if(temp.isFile()){  
          FileInputStream input = new FileInputStream(temp);  
          FileOutputStream output = new FileOutputStream(folderList2[j] + "/" +  
              (temp.getName()).toString());  
          byte[] b = new byte[5120];  
          int len;  
          while ( (len = input.read(b)) != -1) {  
            output.write(b, 0, len);  
          }  
          output.flush();  
          output.close();  
          input.close();  
temp.delete();  
        }  
        if(temp.isDirectory()){//如果是子文件夹  
          folderList.add(folderList[j]+"/"+file[i]);  
          folderList2.add(folderList2[j]+"/"+file[i]);  
        }  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制整个文件夹内容操作出错");  
      e.printStackTrace();  
    }  
}  
movefoldersList[k].delete();  
}  
}  
 
17.以一个文件夹的框架在另一个目录创建文件夹和空文件  
ArrayList<String>folderList=new ArrayList<String>();  
folderList.add(%%1);  
ArrayList<String>folderList2=new ArrayList<String>();  
folderList2.add(%%2);  
for(int j=0;j<folderList.length;j++){  
    (new File(folderList2[j])).mkdirs(); //如果文件夹不存在 则建立新文件夹  
    File folders=new File(folderList[j]);  
    String[] file=folders.list();  
    File temp=null;  
    try {  
      for (int i = 0; i < file.length; i++) {  
        if(folderList[j].endsWith(File.separator)){  
          temp=new File(folderList[j]+"/"+file[i]);  
        }  
        else{  
          temp=new File(folderList[j]+"/"+File.separator+file[i]);  
        }  
          FileInputStream input = new FileInputStream(temp);  
        if(temp.isFile()){  
if (!temp.exists()) {  
temp.createNewFile();  
}  
        }  
        if(temp.isDirectory()){//如果是子文件夹  
          folderList.add(folderList[j]+"/"+file[i]);  
          folderList2.add(folderList2[j]+"/"+file[i]);  
        }  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制整个文件夹内容操作出错");  
      e.printStackTrace();  
    }  
}   
 
18.复制文件  
      int bytesum = 0;  
      int byteread = 0;  
      File oldfile = new File(%%1);  
    try {  
      if (oldfile.exists()) { //文件存在时  
        InputStream inStream = new FileInputStream(oldfile); //读入原文件  
        FileOutputStream fs = new FileOutputStream(new File(%%2,oldfile.getName()));  
        byte[] buffer = new byte[5120];  
        int length;  
        while ( (byteread = inStream.read(buffer)) != -1) {  
          bytesum += byteread; //字节数 文件大小  
          System.out.println(bytesum);  
          fs.write(buffer, 0, byteread);  
        }  
        inStream.close();  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制单个文件操作出错");  
      e.printStackTrace();  
    }   
 
19.复制一个文件夹下所有的文件到另一个目录  
File copyfiles=new File(%%1);  
File[] files=copyfiles.listFiles();  
for(int i=0;i<files.length;i++){  
if(!files[i].isDirectory()){  
      int bytesum = 0;  
      int byteread = 0;  
    try {  
        InputStream inStream = new FileInputStream(files[i]); //读入原文件  
        FileOutputStream fs = new FileOutputStream(new File(%%2,files[i].getName());  
        byte[] buffer = new byte[5120];  
        int length;  
        while ( (byteread = inStream.read(buffer)) != -1) {  
          bytesum += byteread; //字节数 文件大小  
          System.out.println(bytesum);  
          fs.write(buffer, 0, byteread);  
        }  
        inStream.close();  
    } catch (Exception e) {  
      System.out.println("复制单个文件操作出错");  
      e.printStackTrace();  
    }  
}  
}   
 
20.提取扩展名  
String %%2=(new File(%%1)).getName().split(".")[1];   
 
21.提取文件名  
String %%2=(new File(%%1)).getName().split("//")[1];   
 
22.提取文件路径  
String %%2=(new File(%%1)).getPath();   
 
23.替换扩展名  
File replaceExt=new File(%%1);  
replaceExt.renameTo(replaceExt.getName().split(".")[0]+"."+%%2);   
 
24.追加路径  
%%3=%%2+"/"+%%1   
 
25.移动文件  
      int bytesum = 0;  
      int byteread = 0;  
      File oldfile = new File(%%1);  
    try {  
      if (oldfile.exists()) { //文件存在时  
        InputStream inStream = new FileInputStream(oldfile); //读入原文件  
        FileOutputStream fs = new FileOutputStream(new File(%%2,oldfile.getName()));  
        byte[] buffer = new byte[5120];  
        int length;  
        while ( (byteread = inStream.read(buffer)) != -1) {  
          bytesum += byteread; //字节数 文件大小  
          //System.out.println(bytesum);  
          fs.write(buffer, 0, byteread);  
        }  
        inStream.close();  
oldfile.delete();  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制单个文件操作出错");  
      e.printStackTrace();  
    }   
 
26.移动一个文件夹下所有文件到另一个目录  
File movefile=new File(%%1);  
File[] movefiles=movefile.listFiles();  
for(int i=0;i<movefiles.length;i++){  
if(movefiles[i].isFile()){  
      int bytesum = 0;  
      int byteread = 0;  
      File oldfile = new File(movefiles[i]);  
    try {  
      if (oldfile.exists()) { //文件存在时  
        InputStream inStream = new FileInputStream(oldfile); //读入原文件  
        FileOutputStream fs = new FileOutputStream(new File(%%2,oldfile.getName()));  
        byte[] buffer = new byte[5120];  
        int length;  
        while ( (byteread = inStream.read(buffer)) != -1) {  
          bytesum += byteread; //字节数 文件大小  
          //System.out.println(bytesum);  
          fs.write(buffer, 0, byteread);  
        }  
        inStream.close();  
oldfile.delete();  
      }  
    }  
    catch (Exception e) {  
      System.out.println("复制单个文件操作出错");  
      e.printStackTrace();  
    }  
}  
}   
 
27.指定目录下搜索文件  
    private void doSearch(String filter, String path) {  
        File file = new File(path);  
        if(file.exists()) {  
            if(file.isDirectory()) {  
                File[] fileArray = file.listFiles();  
                for(File f:fileArray) {  
                    if(f.isDirectory()) {  
                        doSearch(filter,f.getPath());  
                    } else {  
                        if(f.getName().indexOf(filter) >= 0) {  
                            countFiles++;  
                            result.append(f.getPath() + "\r\n");  
                        }  
                    }  
                    statusShow1.setText(f.getPath());  
                }  
                statusShow2.setText("The numbers of files had been found:" + countFiles);  
            } else {  
                System.out.println("Couldn't open the path!");  
            }  
        } else {  
            System.out.println("The path had been apointed was not Exist!");  
        }  
    }   
 
28.打开对话框  
JFileChooser Jfc = new JFileChooser();            //建立选择档案对话方块盒 Jfc  
%%1 = Jfc.getSelectedFile();   
 
29.文件分割  
//import java.io.*  
try {  
File f=new File(%%1);  
FileInputStream fileInputStream = new FileInputStream(f);  
byte[] buffer = new byte[fileInputStream.available()];  
FileInputStream.read(buffer);  
fileInputStream.close();  
String strFileName = f.getName();  
FileOutputStream fileOutputStream = new FileOutputStream(new File(%%2+"\\"+ strFileName + "1"));  
fileOutputStream.write(buffer,0,buffer.length/2);  
fileOutputStream.close();  
fileOutputStream = new FileOutputStream(new File(%%2+"\\"+ strFileName + "2"));  
fileOutputStream.write(buffer, buffer.length/2, buffer.length-buffer.length/2);  
fileOutputStream.close();  
} catch (ArrayIndexOutOfBoundsException e) {  
System.out.print("using FileStreamDemo src des");  
e.printStackTrace();  
}  
catch(IOException e){  
e.printStackTrace();  
}   
 
30.文件合并  
//import java.io.*  
String strFileName = %%1.substring(%%1.LastIndexOf("\\") + 1);  
try {  
FileInputStream fileInputStream1 = new FileInputStream(new File(%%2 + strFileName + "1"));  
FileInputStream fileInputStream2 = new FileInputStream(new File(%%2 + strFileName + "2"));  
byte[] buffer = new byte[fileInputStream1.available()+fileInputStream2.available()];  
FileInputStream.read(buffer, 0, fileInputStream1.available());  
FileInputStream2.read(buffer, fileInputStream1.available(), fileInputStream2.available());  
fileInputStream.close();  
fileInputStream2.close();  
FileOutputStream fileOutputStream = new FileOutputStream(new File(%%2+"\\"+ strFileName));  
fileOutputStream.write(buffer,0,buffer.length);  
fileOutputStream.close();  
catch(IOException e){  
e.printStackTrace();  
}   
 
31.文件简单加密  
//读文件  
FileStream fsr = new FileStream(%%1, FileMode.Open, FileAccess.Read);  
byte[] btArr = new byte[fsr.Length];  
fsr.Read(btArr, 0, btArr.Length);  
fsr.Close();  
for (int i = 0; i < btArr.Length; i++) //加密  
{  
    int ibt = btArr[i];  
    ibt += 100;  
    ibt %= 256;  
    btArr[i] = Convert.ToByte(ibt);  
}  
//写文件  
string strFileName = Path.GetExtension(%%1);  
FileStream fsw = new FileStream(%%2+"/" + "enc_" + strFileName, FileMode.Create, FileAccess.Write);  
fsw.Write(btArr, 0, btArr.Length);  
fsw.Close();   
 
32.文件简单解密  
FileStream fsr = new FileStream(%%1, FileMode.Open, FileAccess.Read);  
byte[] btArr = new byte[fsr.Length];  
fsr.Read(btArr, 0, btArr.Length);  
fsr.Close();  
for (int i = 0; i < btArr.Length; i++)　//解密  
{  
    int ibt = btArr[i];  
    ibt -= 100;  
    ibt += 256;  
    ibt %= 256;  
    btArr[i] = Convert.ToByte(ibt);  
}  
//写文件  
string strFileName = Path.GetExtension(%%1);  
FileStream fsw = new FileStream(%%2 +"/" + strFileName, FileMode.Create, FileAccess.Write);  
fsw.Write(btArr, 0, btArr.Length);  
fsw.Close();   
 
33.文件简单解密  
//import java.io.*  
try {  
File f=new File(%%1);  
String strFileName = f.getName();  
FileInputStream fileInputStream = new FileInputStream(%%2+"\\enc_"+strFilename);  
byte[] buffer = new byte[fileInputStream.available()];  
FileInputStream.read(buffer);  
fileInputStream.close();  
for(int i=0;i<buffer.length;i++)  
{  
int ibt=buffer[i];  
ibt-=100;  
ibt+=256;  
ibt%=256;  
buffer[i]=(byte)ibt;  
}  
FileOutputStream fileOutputStream = new FileOutputStream(f);  
fileOutputStream.write(buffer,0,buffer.length);  
fileOutputStream.close();  
}  
catch(ArrayIndexOutOfBoundException e){  
e.printStackTrace();  
}  
catch(IOException e){  
e.printStackTrace();  
}   
 
34.读取ini文件属性  
//import java.io.*  
//import java.util.*;  
//import java.util.regex.*;   
//private HashMap configMap=null;  
private Map configMap=null;  
if(configMap==null) {  
String strLine=null;  
String currentNode=null;  
String previousNode=null;  
Vector vec=new Vector();  
int row=0;  
FileReader fileReader = new FileReader(%%1);  
BufferedReader bufferedReader=new BufferedReader(fileReader);  
try {  
while((strLine=bufferedReader.readLine())!=null) {  
String oneLine=strLine.trim();  
if(oneLine.length()>=1) {  
Pattern p=Pattern.compile("\\[\\s*.*\\s*\\]");  
int nodelen=oneLine.split("[;]").length;  
String[] strArray1=new String[4];  
if(nodelen==1) {  
oneLine=oneLine.split("[;]")[0].trim();  
}  
else if(nodelen==2) {  
strArray1[3]=oneLine.split("[;]")[1].trim();  
oneLine=oneLine.split("[;]")[0].trim();  
}  
Matcher m=p.matche(oneLine);  
if(m.matches()) {  
strArray1[0]="@Node";  
strArray1[1]=oneLine;  
strArray1[2]="";  
} else {  
int keylen=oneLine.split("=").length;  
if(keylen==1) {  
strArray1[0]="@Key";  
strArray1[1]=oneLine.split("=")[0];  
strArray1[2]="";  
} else if(kenlen==2) {  
strArray1[0]="@Key";  
strArray1[1]=oneLine.split("=")[0];  
strArray1[2]=oneLine.split("=")[1];  
} else {  
strArray1[0]="@ElementError";  
strArray1[1]="";  
strArray1[2]="";  
strArray1[3]="";  
}  
}  
if(strArray1[0].equals("@Node")) {  
previousNode=currentNode;  
currentNode=strArray1[1];  
if(row>0) {  
configMap.put(previousNode,vec.elementAt(0));  
//"size:"+configMap.size()  
vec.clear();  
row=0;  
}  
} else if(strArray1[0].equals("@Key") && row==0) {  
Properties ht=new Properties();  
ht.setProperty(strArray1[1],strArray1[2]);  
vec.add(0,ht);  
row++;  
}  
} else if(strArray1[0].equals("@Key") && row>0) {  
Properties ht2=new Properties();  
ht2.put(strArray1[1],strArray1[2]);  
vec.clear();  
vec.add(0,ht2);  
row++;  
}  
}  
}  
configMap.put(currentNode,vec.elementAt(0));  
} catch (FileNotFoundException e) {  
configMap=null;  
e.printStackTrace();  
} catch (IOException e) {  
configMap=null;  
e.printStackTrace();  
} finally {  
vec.clear();  
bufferedReader.close();  
fileReader.close();  
}  
}  
String nodeKey="["+%%2+"]";  
Properties ht=(Properties)configMap.get(nodeKey);  
//"ht:"+ht.toString()  
//"key:"+%%3  
CString %%4=null;  
if(ht.containsKey(%%3)) {  
try {  
%%4=ht.getProperty(%%3);  
} catch (NullPointException e) {  
e.printStackTrace();  
}  
}   
 
35.合并一个文件下所有的文件  
File combinefiles=new File(%%1);  
File[] files=combinefiles.listFiles();  
FileOutputStream fs;  
try {  
fs=new FileOutputStream(new File(%%2));  
}  
catch(IOException e){  
e.printStackTrace();  
}  
for(int i=0;i<files.length;i++){  
if(files[i].isFile()){  
int bytesum=0;  
int byteread=0;  
try {   
FileInputStream inStream=new FileInputStream(files[i]);  
byte[] buffer = new byte[5120];  
int length;  
while((byteread=inStream.read(buffer))!=-1){  
bytesum+=byteread;  
fs.write(buffer,0,byteread);  
}  
inStream.close();  
}  
catch(Exception e){  
//复制文件出错  
e.printStackTrace();  
}  
}  
}  
try {  
fs.close();  
}  
catch(IOException e){  
{  
e.printStackTrace();  
}   
 
36.写入ini文件属性  
//import java.io.*  
//import java.util.*;  
//import java.util.regex.*;   
//private HashMap configMap=null;  
private Map configMap=null;  
if(configMap==null) {  
String strLine=null;  
String currentNode=null;  
String previousNode=null;  
Vector vec=new Vector();  
int row=0;  
FileReader fileReader = new FileReader(%%1);  
BufferedReader bufferedReader=new BufferedReader(fileReader);  
try {  
while((strLine=bufferedReader.readLine())!=null) {  
String oneLine=strLine.trim();  
if(oneLine.length()>=1) {  
Pattern p=Pattern.compile("\\[\\s*.*\\s*\\]");  
int nodelen=oneLine.split("[;]").length;  
String[] strArray1=new String[4];  
if(nodelen==1) {  
oneLine=oneLine.split("[;]")[0].trim();  
}  
else if(nodelen==2) {  
strArray1[3]=oneLine.split("[;]")[1].trim();  
oneLine=oneLine.split("[;]")[0].trim();  
}  
Matcher m=p.matche(oneLine);  
if(m.matches()) {  
strArray1[0]="@Node";  
strArray1[1]=oneLine;  
strArray1[2]="";  
} else {  
int keylen=oneLine.split("=").length;  
if(keylen==1) {  
strArray1[0]="@Key";  
strArray1[1]=oneLine.split("=")[0];  
strArray1[2]="";  
} else if(kenlen==2) {  
strArray1[0]="@Key";  
strArray1[1]=oneLine.split("=")[0];  
strArray1[2]=oneLine.split("=")[1];  
} else {  
strArray1[0]="@ElementError";  
strArray1[1]="";  
strArray1[2]="";  
strArray1[3]="";  
}  
}  
if(strArray1[0].equals("@Node")) {  
previousNode=currentNode;  
currentNode=strArray1[1];  
if(row>0) {  
configMap.put(previousNode,vec.elementAt(0));  
//"size:"+configMap.size()  
vec.clear();  
row=0;  
}  
} else if(strArray1[0].equals("@Key") && row==0) {  
Properties ht=new Properties();  
ht.setProperty(strArray1[1],strArray1[2]);  
vec.add(0,ht);  
row++;  
}  
} else if(strArray1[0].equals("@Key") && row>0) {  
Properties ht2=new Properties();  
ht2.put(strArray1[1],strArray1[2]);  
vec.clear();  
vec.add(0,ht2);  
row++;  
}  
}  
}  
configMap.put(currentNode,vec.elementAt(0));  
} catch (FileNotFoundException e) {  
configMap=null;  
e.printStackTrace();  
} catch (IOException e) {  
configMap=null;  
e.printStackTrace();  
} finally {  
vec.clear();  
bufferedReader.close();  
fileReader.close();  
}  
}  
String nodeKey="["+%%2+"]";  
Properties ht=null;  
if(configMap.containsKey(nodeKey)) {  
ht=(Properties)configMap.get(nodeKey);  
} else {  
ht=(Properties)configMap.get(nodeKey,%%3);  
}  
try {  
ht.setProperty(%%3,%%4);  
} catch (NullPointException e) {   
e.printStackTrace();  
}  
FileWriter fw = new FileWriter(%%1);  
BufferedWriter bw=new BufferedWriter(fw);  
Set keys=configMap.keySet();  
Iterator ite=keys.iterator();  
while(ite.hasNext()) {  
String oneKey=(String)ite.next();  
bw.WriteLine(oneKey);  
ht=(Properties)configMap.get(oneKey);  
ht.list(new PrintWriter(bw,true));  
}   
 
37.获得当前路径  
this.getClass().getResource("/").getPath()   
 
38.读取XML数据库  
//import java.io.*;  
//import javax.xml.parsers.*;  
//import org.xml.sax.*;  
//import org.w3c.dom.*;  
private Document document;  
File xml_file=new File(%%1);  
DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();  
try {  
DocumentBuilder builder=factory.newDocumentBuilder();  
document=builder.parse(xml_file);  
} catch(Exception e) {  
e.printStackTrace();  
}  
String subNodeTag=%%2;  
Element rootNode=document.getDocumentElement();  
//%%2="serverList" //%%4="id" //%%6="port"  
//%%3="server" //%%5="ipaddr"  
NodeList nlist=rootNode.getElementsByTagName(subNodeTag);  
int len=nlist.getLength();  
Node x=null;  
for(int i=0;i<len;i++) {  
x=nlist.item(i);  
String getNodeAttrValue=null;  
NamedNodeMap attrList=node.getAttributes();  
for(int j=0;j<attrList.getLength();j++) {  
if(attrList.item(j).getNodeName().compareTo(%%7)==0) {  
getNodeAttrValue=attrList.item(j).getNodeValue();  
break;  
}  
}  
if(getNodeAttrValue.compareTo(%%8)==0)  
break;  
}  
String %%9=null;  
if(x!=null) {  
NodeList nlist=node.getChildNodes();  
int len=nlist.getLength();  
Node currentNode;  
String nodeName;  
for(int i=0;i<len;i++) {  
currentNode=nlist.item(i);  
nodeName=currentNode.getNodeName();  
if(nodeName.equals(%%5)==0) {  
%%9=document.getElementValue(currentNode);  
break;  
}  
}  
}   
 
39.写入XML数据库  
//import java.io.*;  
//import javax.xml.parsers.*;  
//import org.xml.sax.*;  
//import org.w3c.dom.*;  
//import javax.xml.transform.*;  
//import javax.xml.transform.dom.*;  
//import javax.xml.transform.stream.*;  
private Document document;  
private Element node;  
File xml_file=new File(%%1);  
DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();  
try {  
DocumentBuilder builder=factory.newDocumentBuilder();  
document=builder.parse(xml_file);  
} catch(Exception e) {  
e.printStackTrace();  
}  
String subNodeTag=%%2;  
Element rootNode=document.getDocumentElement();  
//%%2="serverList" //%%4="id" //%%6="port"  
//%%3="server" //%%5="ipaddr"  
NodeList nlist=rootNode.getElementByTagName(subNodeTag);  
node=document.createElement(%%3);  
node.setAttribute(%%4,nlist.getLength()+1).toString());  
node.appendChild(document.createTextNode("\n");  
Element ipNode=document.createElement(%%5);  
ipNode.appendChild(document.createTextNode(%%8));  
node.appendChild(ipNode);  
node.appendChild(document,createTextNode("\n");  
Element port=document.createElement(%%6);  
port.appendChild(document.createTextNode(%%9));  
node.appendChild(port);  
node.appendChild(document,createTextNode("\n");  
nlist.appendChild(node);  
TransformerFactory tFactory=TransformerFactory.newInstance();  
Transformer transformer=null;  
try {  
transformer=tFactory.newTransformer();  
DOMSource source=new DOMSource(document);  
StreamResult result=new StreamResult(xml_file);  
transformer.transform(source,result);  
} catch(Exception e) {  
e.printStackTrace();  
}   
 
40.ZIP压缩文件  
//import java.io.*;  
//import java.util.zip.*;  
//创建文件输入流对象  
FileInputStream fis=new FileInputStream(%%1);  
//创建文件输出流对象  
FileOutputStream fos=new FileOutputStream(%%2);  
//创建ZIP数据输出流对象  
ZipOutputStream zipOut=new ZipOutputStream(fos);  
//创建指向压缩原始文件的入口  
ZipEntry entry=new ZipEntry(args[0]);  
zipOut.putNextEntry(entry);  
//向压缩文件中输出数据  
int nNumber;  
byte[] buffer=new byte[1024];  
while((nNumber=fis.read(buffer))!=-1)  
zipOut.write(buffer,0,nNumber);  
//关闭创建的流对象  
zipOut.close();  
fos.close();  
fis.close();  
}  
catch(IOException e)   
{  
System.out.println(e);  
}   
 
41.ZIP解压缩  
//import java.io.*;  
//import java.util.zip.*;  
try{  
//创建文件输入流对象实例  
FileInputStream fis=new FileInputStream(%%1);  
//创建ZIP压缩格式输入流对象实例  
ZipInputStream zipin=new ZipInputStream(fis);  
//创建文件输出流对象实例  
FileOutputStream fos=new FileOutputStream(%%2);  
//获取Entry对象实例  
ZipEntry entry=zipin.getNextEntry();  
byte[] buffer=new byte[1024];  
int nNumber;  
while((nNumber=zipin.read(buffer,0,buffer.length))!=-1)  
fos.write(buffer,0,nNumber);  
//关闭文件流对象  
zipin.close();  
fos.close();  
fis.close();  
}  
catch(IOException e) {  
System.out.println(e);  
}   
 
42.递归删除目录中的文件  
//import java.io.*;  
//import java.util.*;  
ArrayList<String> folderList = new ArrayList<String>();  
folderList.add(%%1);  
for (int j = 0; j < folderList.size(); j++) {  
File file = new File(folderList.get(j));  
File[] files = file.listFiles();  
ArrayList<File> fileList = new ArrayList<File>();  
for (int i = 0; i < files.length; i++) {  
if (files[i].isDirectory()) {  
folderList.add(files[i].getPath());  
} else {  
fileList.add(files[i]);  
}  
}  
for (File f : fileList) {  
f.delete();  
}  
}   
 
43.ZIP压缩文件夹  
//import java.io.*;  
//import org.apache.tools.zip.ZipOutputStream; //这个包在ant.jar里，要到官方网下载  
//import java.util.zip.*;  
try {  
String zipFileName = %%2; //打包后文件名字  
File f=new File(%%1);  
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFileName));  
String base= "";  
if (f.isDirectory()) {  
   File[] fl = f.listFiles();  
   out.putNextEntry(new org.apache.tools.zip.ZipEntry(base + "/"));  
   base = base.length() == 0 ? "" : base + "/";  
   for (int i = 0; i < fl.length; i++) {  
   zip(out, fl[i], base + fl[i].getName());  
}  
}else {  
   out.putNextEntry(new org.apache.tools.zip.ZipEntry(base));  
   FileInputStream in = new FileInputStream(f);  
   int b;  
   while ( (b = in.read()) != -1) {  
    out.write(b);  
}  
in.close();  
}  
out.close();  
}catch (Exception ex) {  
   ex.printStackTrace();  
}   
 
44.Java验证DTD  
try   {   
      InputStream   in=new   FileInputStream(filePath);       
SAXReader   saxReader   =   new   SAXReader();   
this.document   =   saxReader.read(in);         
DocumentBuilderFactory       factory       =       null;     
factory       =       DocumentBuilderFactory.newInstance();         
    //进行dtd检查         
factory.setValidating(true);         
}   catch   (Exception   e)   {   
}   
 
45.验证Schema  
String xsdFileName = \"Q:\\\\_dev_stu\\\\xsdtest\\\\src\\\\note.xsd\";   
try {   
//创建默认的XML错误处理器   
XMLErrorHandler errorHandler = new XMLErrorHandler();   
//获取基于 SAX 的解析器的实例   
SAXParserFactory factory = SAXParserFactory.newInstance();   
//解析器在解析时验证 XML 内容。   
factory.setValidating(true);   
//指定由此代码生成的解析器将提供对 XML 名称空间的支持。   
factory.setNamespaceAware(true);   
//使用当前配置的工厂参数创建 SAXParser 的一个新实例。   
SAXParser parser = factory.newSAXParser();   
//创建一个读取工具   
SAXReader xmlReader = new SAXReader();   
//获取要校验xml文档实例   
Document xmlDocument = (Document) xmlReader.read(new File(xmlFileName));   
//设置 XMLReader 的基础实现中的特定属性。核心功能和属性列表可以在 [url]http://sax.sourceforge.net/?selected=get-set[/url] 中   
 
找到。   
parser.setProperty(   
\"http://java.sun.com/xml/jaxp/properties/schemaLanguage",   
\"http://www.w3.org/2001/XMLSchema");   
parser.setProperty(   
\"http://java.sun.com/xml/jaxp/properties/schemaSource",   
\"file:\" + xsdFileName);   
//创建一个SAXValidator校验工具，并设置校验工具的属性   
SAXValidator validator = new SAXValidator(parser.getXMLReader());   
//设置校验工具的错误处理器，当发生错误时，可以从处理器对象中得到错误信息。   
validator.setErrorHandler(errorHandler);   
//校验   
validator.validate(xmlDocument);   
 
XMLWriter writer = new XMLWriter(OutputFormat.createPrettyPrint());   
//如果错误信息不为空，说明校验失败，打印错误信息   
if (errorHandler.getErrors().hasContent()) {   
     System.out.println(\"XML文件通过XSD文件校验失败！\");   
     writer.write(errorHandler.getErrors());   
} else {   
     System.out.println(\"Good! XML文件通过XSD文件校验成功！\");   
}   
} catch (Exception ex) {   
System.out.println(\"XML文件: \" + xmlFileName + \" 通过XSD文件:\" + xsdFileName + \"检验失败。\n原因： \" + ex.getMessage   
 
());   
ex.printStackTrace();   
}   
     }   
 
46.Grep  
//import java.util.regex.Pattern;   
//import java.util.regex.Matcher;   
//import java.io.FileReader;   
//import java.io.BufferedReader;   
//import java.io.IOException;   
 
/**  
* Simple implementation of the ubiquitous grep command.  
* First argument is the regular expression to search for (remember to  
* quote and/or escape as appropriate). All following arguments are  
* filenames to read and search for the regular expression.  
*  
* Created: April, 2002  
* @author Ron Hitchens ([e-mail])  
* @version $Id: SimpleGrep.java,v 1.1 2002/05/07 02:21:08 ron Exp $  
*/   
public static void main (String [] argv)   
throws Exception   
{   
if (argv.length < 2) { // 如果参数行没有输入参数，结束程序   
System.out.println ("Usage: regex file [ ... ]");   
return;   
}   
 
Pattern pattern = Pattern.compile (argv [0]); // 第一个参数为需要匹配的字符串   
Matcher matcher = pattern.matcher ("");   
 
// 一次读取各个文件   
for (int i = 1; i < argv.length; i++) {   
String file = argv [i]; // 第2个参数开始，均为文件名。   
BufferedReader br = null;   
String line;   
 
try {   
br = new BufferedReader (new FileReader (file)); // 打开文件   
} catch (IOException e) {   
// 没有打开文件，则产生异常   
System.err.println ("Cannot read '" + file   
+ "': " + e.getMessage());   
continue;   
}   
 
while ((line = br.readLine()) != null) { // 读入一行，直到文件结束   
matcher.reset (line); // 匹配字符串   
 
if (matcher.find()) { // 如果有匹配的字符串，则输出   
System.out.println (file + ": " + line);   
}   
}   
 
br.close(); // 关闭文件  
}  
}  

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/hias_asia/archive/2009/04/16/4084403.aspx