文件读、写

package com.fxz.file;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.fxz.vo.Adress;
/**
 * 读取文件
 * @author Administrator
 *
 */
public class FileToReader {

 
	/**
	 * 读取文件，返回对象集合
	 * @param filePath
	 * @return
	 */
	public static List<Adress> readFileToArray(String filePath){
		
		List<Adress> list = new ArrayList<Adress>();
		File f = new File(filePath) ;
		
		//如果文件存在
		if(f.exists()){
			try {
				BufferedReader reader = new BufferedReader(new FileReader(f));
				String txt ;
				Adress adress = null ;
				while((txt = reader.readLine()) != null){
					if(!"".equals(txt)){
						String id = txt.substring(0, 4);
						String name = txt.substring(4, txt.length());
						adress = new Adress(id , name);
						list.add(adress);
					}
				}
				reader.close();
			} catch (FileNotFoundException e) {
				System.out.println("文件不存在2");
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}else {
			System.out.println("文件不存在");
		}
		 
		return list ;
	}

	public static void main(String args[]) {
		long startTime=System.currentTimeMillis(); 
		List<Adress> list = new ArrayList<Adress>();
		list = readFileToArray("c:\\1.txt");
		int i = 1 ;
		for (Adress adress : list) {
			System.out.println(i++ + "、 " + adress.getId() + "    =====    "  + adress.getName());
		}
		long endTime=System.currentTimeMillis(); //获取结束时间  
		System.out.println("程序运行时间： "+(endTime - startTime)+"ms"); 
	}
}

 

 package com.fxz.file;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 * 文件写入
 * @author 方小洲
 */
public class FileToWrite {

	
	
	
	/**
	 * 利用FileOutputStream  写入文件
	 * @param filePath	文件路径
	 * @param content	写入的内容
	 * @param isCover	是否覆盖
	 * @return
	 */
	public static boolean WriteFileWithFileOutputStream(String filePath , String content , boolean isCover ){
		boolean isSuccess = true ;
		StringBuffer str = new StringBuffer();
		File f = new File(filePath) ;
		
		long begin = System.currentTimeMillis() ;
		
		//存在并不覆盖,读取原文件的内容
		if(!isCover && f.exists()){
			try {
				BufferedReader reader  = new BufferedReader(new FileReader(f));			//读取文件
				String tmp ;
				while((tmp = reader.readLine()) != null){
					str.append(tmp);
				}
				str.append("\n");
				reader.close();
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
		str.append(content);
		
		//写入文件
		try {
			FileOutputStream fos = new FileOutputStream(f);
			fos.write(str.toString().getBytes());
			fos.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		long end = System.currentTimeMillis();
		
		System.out.println(end - begin);
		 
		return isSuccess;
	}
	

	/**
	 * 利用FileWriter 写入文件
	 * @param filePath	文件路径
	 * @param content	写入的内容
	 * @param isCover	是否覆盖
	 * @return
	 */
	public static boolean WriteFileWithBufferedOutputStream(String filePath , String content , boolean isCover ){
		boolean isSuccess = true ;
		StringBuffer str = new StringBuffer();
		File f = new File(filePath) ;
		
		//存在并不覆盖,读取原文件的内容
		if(!isCover && f.exists()){
			try {
				BufferedReader reader  = new BufferedReader(new FileReader(f));			//读取文件
				String tmp ;
				while((tmp = reader.readLine()) != null){
					str.append(tmp);
				}
				str.append("\n");
				reader.close();
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
		str.append(content);
		
		//写入文件
		try {
			BufferedOutputStream writer = new BufferedOutputStream(new FileOutputStream(f));
			writer.write(str.toString().getBytes());
			writer.flush();
			writer.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		 
		return isSuccess;
	}
	
	
	
  
	/**
	 * 利用FileWriter 写入文件
	 * @param filePath	文件路径
	 * @param content	写入的内容
	 * @param isCover	是否覆盖
	 * @return
	 */
	public static boolean WriteFileWithFileWriter(String filePath , String content , boolean isCover ){
		boolean isSuccess = true ;
		StringBuffer str = new StringBuffer();
		File f = new File(filePath) ;
		
		//存在并不覆盖,读取原文件的内容
		if(!isCover && f.exists()){
			try {
				BufferedReader reader  = new BufferedReader(new FileReader(f));			//读取文件
				String tmp ;
				while((tmp = reader.readLine()) != null){
					str.append(tmp);
				}
				str.append("\n");
				reader.close();
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
		str.append(content);
		
		//写入文件
		try {
			BufferedWriter writer = new BufferedWriter(new FileWriter(f));
			writer.write(str.toString());
			writer.flush();
			writer.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		 
		return isSuccess;
	}
	
	
	public static void main(String[] args) {
		//WriteFileWithFileWriter("c:\\3.txt", "方小洲", true);
		WriteFileWithBufferedOutputStream("c:\\3.txt", "ssssssssssssssfddsf方小洲", false);
	}
}