Android快速开发工具类

来源：http://blog.csdn.net/lmj623565791/article/details/38965311

Android开发必备工具类集合

 

1、日志工具类L.java

 

package com.zhy.utils;

import android.util.Log;

/**
 * Log统一管理类
 *
 *
 *
 */
public class L
{

    private L()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    public static boolean isDebug = true;// 是否需要打印bug，可以在application的onCreate函数里面初始化
    private static final String TAG = "way";

    // 下面四个是默认tag的函数
    public static void i(String msg)
    {
        if (isDebug)
            Log.i(TAG, msg);
    }

    public static void d(String msg)
    {
        if (isDebug)
            Log.d(TAG, msg);
    }

    public static void e(String msg)
    {
        if (isDebug)
            Log.e(TAG, msg);
    }

    public static void v(String msg)
    {
        if (isDebug)
            Log.v(TAG, msg);
    }

    // 下面是传入自定义tag的函数
    public static void i(String tag, String msg)
    {
        if (isDebug)
            Log.i(tag, msg);
    }

    public static void d(String tag, String msg)
    {
        if (isDebug)
            Log.i(tag, msg);
    }

    public static void e(String tag, String msg)
    {
        if (isDebug)
            Log.i(tag, msg);
    }

    public static void v(String tag, String msg)
    {
        if (isDebug)
            Log.i(tag, msg);
    }
}

 

网上看到的类，注释上应该原创作者的名字，很简单的一个类；网上也有很多提供把日志记录到SDCard上的，不过我是从来没记录过，所以引入个最简单的，大家可以进行评价是否需要扩充~~

2、Toast统一管理类 

 

package com.zhy.utils;

import android.content.Context;
import android.widget.Toast;

/**
 * Toast统一管理类
 *
 */
public class T
{

    private T()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    public static boolean isShow = true;

    /**
     * 短时间显示Toast
     *
     * @param context
     * @param message
     */
    public static void showShort(Context context, CharSequence message)
    {
        if (isShow)
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
    }

    /**
     * 短时间显示Toast
     *
     * @param context
     * @param message
     */
    public static void showShort(Context context, int message)
    {
        if (isShow)
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
    }

    /**
     * 长时间显示Toast
     *
     * @param context
     * @param message
     */
    public static void showLong(Context context, CharSequence message)
    {
        if (isShow)
            Toast.makeText(context, message, Toast.LENGTH_LONG).show();
    }

    /**
     * 长时间显示Toast
     *
     * @param context
     * @param message
     */
    public static void showLong(Context context, int message)
    {
        if (isShow)
            Toast.makeText(context, message, Toast.LENGTH_LONG).show();
    }

    /**
     * 自定义显示Toast时间
     *
     * @param context
     * @param message
     * @param duration
     */
    public static void show(Context context, CharSequence message, int duration)
    {
        if (isShow)
            Toast.makeText(context, message, duration).show();
    }

    /**
     * 自定义显示Toast时间
     *
     * @param context
     * @param message
     * @param duration
     */
    public static void show(Context context, int message, int duration)
    {
        if (isShow)
            Toast.makeText(context, message, duration).show();
    }

}

 

也是非常简单的一个封装，能省则省了~~

3、SharedPreferences封装类SPUtils

 

import java.lang.reflect.InvocationTargetException;  
import java.lang.reflect.Method;  
import java.util.Map;  
  
import android.content.Context;  
import android.content.SharedPreferences;  
  
public class SPUtils  
{  
    /** 
     * 保存在手机里面的文件名 
     */  
    public static final String FILE_NAME = "share_data";  
	public static final String LOGIN_DATA="loginData";
	public static final String IS_LOGIN= "IS_LOGIN";
  
    /** 
     * 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法 
     *  
     * @param context 
     * @param key 
     * @param object 
     */  
    public static void put(Context context, String key, Object object)  
    {  
  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
        SharedPreferences.Editor editor = sp.edit();  
  
        if (object instanceof String)  
        {  
            editor.putString(key, (String) object);  
        } else if (object instanceof Integer)  
        {  
            editor.putInt(key, (Integer) object);  
        } else if (object instanceof Boolean)  
        {  
            editor.putBoolean(key, (Boolean) object);  
        } else if (object instanceof Float)  
        {  
            editor.putFloat(key, (Float) object);  
        } else if (object instanceof Long)  
        {  
            editor.putLong(key, (Long) object);  
        } else  
        {  
            editor.putString(key, object.toString());  
        }  
  
        //SharedPreferencesCompat.apply(editor);  
		editor.commit();
    }  
  
    /** 
     * 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值 
     *  
     * @param context 
     * @param key 
     * @param defaultObject 
     * @return 
     */  
    public static Object get(Context context, String key, Object defaultObject)  
    {  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
  
        if (defaultObject instanceof String)  
        {  
            return sp.getString(key, (String) defaultObject);  
        } else if (defaultObject instanceof Integer)  
        {  
            return sp.getInt(key, (Integer) defaultObject);  
        } else if (defaultObject instanceof Boolean)  
        {  
            return sp.getBoolean(key, (Boolean) defaultObject);  
        } else if (defaultObject instanceof Float)  
        {  
            return sp.getFloat(key, (Float) defaultObject);  
        } else if (defaultObject instanceof Long)  
        {  
            return sp.getLong(key, (Long) defaultObject);  
        }  
  
        return null;  
    }  
  
    /** 
     * 移除某个key值已经对应的值 
     * @param context 
     * @param key 
     */  
    public static void remove(Context context, String key)  
    {  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
        SharedPreferences.Editor editor = sp.edit();  
        editor.remove(key);  
        //SharedPreferencesCompat.apply(editor);  
		
		editor.commit();
    }  
  
    /** 
     * 清除所有数据 
     * @param context 
     */  
    public static void clear(Context context)  
    {  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
        SharedPreferences.Editor editor = sp.edit();  
        editor.clear();  
        SharedPreferencesCompat.apply(editor);  
    }  
  
    /** 
     * 查询某个key是否已经存在 
     * @param context 
     * @param key 
     * @return 
     */  
    public static boolean contains(Context context, String key)  
    {  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
        return sp.contains(key);  
    }  
  
    /** 
     * 返回所有的键值对 
     *  
     * @param context 
     * @return 
     */  
    public static Map<String, ?> getAll(Context context)  
    {  
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME,  
                Context.MODE_PRIVATE);  
        return sp.getAll();  
    }  
  
    /** 
     * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 
     *  
     * @author zhy 
     *  
     */  
    private static class SharedPreferencesCompat  
    {  
        private static final Method sApplyMethod = findApplyMethod();  
  
        /** 
         * 反射查找apply的方法 
         *  
         * @return 
         */  
        @SuppressWarnings({ "unchecked", "rawtypes" })  
        private static Method findApplyMethod()  
        {  
            try  
            {  
                Class clz = SharedPreferences.Editor.class;  
                return clz.getMethod("apply");  
            } catch (NoSuchMethodException e)  
            {  
            }  
  
            return null;  
        }  
  
        /** 
         * 如果找到则使用apply执行，否则使用commit 
         *  
         * @param editor 
         */  
        public static void apply(SharedPreferences.Editor editor)  
        {  
            try  
            {  
                if (sApplyMethod != null)  
                {  
                    sApplyMethod.invoke(editor);  
                    return;  
                }  
            } catch (IllegalArgumentException e)  
            {  
            } catch (IllegalAccessException e)  
            {  
            } catch (InvocationTargetException e)  
            {  
            }  
            editor.commit();  
        }  
    }  
  
}  

 

调用判断是否登录
isLogin=(Boolean) SPUtil.get(getActivity(), SPUtil.IS_LOGIN, false);

存储登录状态:
//保存登录状态
SPUtil.set(LoginActivity.this, SPUtil.IS_LOGIN, true);
//保存登录个人信息
SPUtil.set(LoginActivity .this, SPUtil.LOGIN_DATA, result);

退出登录:
SPUtil.setParam(MySettingsActivity.this, SPUtil.IS_LOGIN, false);
SPUtil.removeParam(MySettingsActivity.this, SPUtil.LOGIN_DATA);

 

对SharedPreference的使用做了建议的封装，对外公布出put，get，remove，clear等等方法；

 

注意一点，里面所有的commit操作使用了SharedPreferencesCompat.apply进行了替代，目的是尽可能的使用apply代替commit

首先说下为什么，因为commit方法是同步的，并且我们很多时候的commit操作都是UI线程中，毕竟是IO操作，尽可能异步；

所以我们使用apply进行替代，apply异步的进行写入；

但是apply相当于commit来说是new API呢，为了更好的兼容，我们做了适配；

SharedPreferencesCompat也可以给大家创建兼容类提供了一定的参考~~

 

4、单位转换类 DensityUtils

 

package com.zhy.utils;

import android.content.Context;
import android.util.TypedValue;

/**
 * 常用单位转换的辅助类
 *
 *
 *
 */
public class DensityUtils
{
    private DensityUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * dp转px
     *
     * @param context
     * @param val
     * @return
     */
    public static int dp2px(Context context, float dpVal)
    {
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                dpVal, context.getResources().getDisplayMetrics());
    }

    /**
     * sp转px
     *
     * @param context
     * @param val
     * @return
     */
    public static int sp2px(Context context, float spVal)
    {
        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
                spVal, context.getResources().getDisplayMetrics());
    }

    /**
     * px转dp
     *
     * @param context
     * @param pxVal
     * @return
     */
    public static float px2dp(Context context, float pxVal)
    {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (pxVal / scale);
    }

    /**
     * px转sp
     *
     * @param fontScale
     * @param pxVal
     * @return
     */
    public static float px2sp(Context context, float pxVal)
    {
        return (pxVal / context.getResources().getDisplayMetrics().scaledDensity);
    }

}

 

5、SD卡相关辅助类 SDCardUtils

package com.zhy.utils;

import java.io.File;

import android.os.Environment;
import android.os.StatFs;

/**
 * SD卡相关的辅助类
 *
 *
 *
 */
public class SDCardUtils
{
    private SDCardUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * 判断SDCard是否可用
     *
     * @return
     */
    public static boolean isSDCardEnable()
    {
        return Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED);

    }

    /**
     * 获取SD卡路径
     *
     * @return
     */
    public static String getSDCardPath()
    {
        return Environment.getExternalStorageDirectory().getAbsolutePath()
                + File.separator;
    }

    /**
     * 获取SD卡的剩余容量 单位byte
     *
     * @return
     */
    public static long getSDCardAllSize()
    {
        if (isSDCardEnable())
        {
            StatFs stat = new StatFs(getSDCardPath());
            // 获取空闲的数据块的数量
            long availableBlocks = (long) stat.getAvailableBlocks() - 4;
            // 获取单个数据块的大小（byte）
            long freeBlocks = stat.getAvailableBlocks();
            return freeBlocks * availableBlocks;
        }
        return 0;
    }

    /**
     * 获取指定路径所在空间的剩余可用容量字节数，单位byte
     *
     * @param filePath
     * @return 容量字节 SDCard可用空间，内部存储可用空间
     */
    public static long getFreeBytes(String filePath)
    {
        // 如果是sd卡的下的路径，则获取sd卡可用容量
        if (filePath.startsWith(getSDCardPath()))
        {
            filePath = getSDCardPath();
        } else
        {// 如果是内部存储的路径，则获取内存存储的可用容量
            filePath = Environment.getDataDirectory().getAbsolutePath();
        }
        StatFs stat = new StatFs(filePath);
        long availableBlocks = (long) stat.getAvailableBlocks() - 4;
        return stat.getBlockSize() * availableBlocks;
    }

    /**
     * 获取系统存储路径
     *
     * @return
     */
    public static String getRootDirectoryPath()
    {
        return Environment.getRootDirectory().getAbsolutePath();
    }


}

 

 

6、屏幕相关辅助类 ScreenUtils

 

package com.zhy.utils;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Rect;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.WindowManager;

/**
 * 获得屏幕相关的辅助类
 *
 *
 *
 */
public class ScreenUtils
{
    private ScreenUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * 获得屏幕高度
     *
     * @param context
     * @return
     */
    public static int getScreenWidth(Context context)
    {
        WindowManager wm = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(outMetrics);
        return outMetrics.widthPixels;
    }

    /**
     * 获得屏幕宽度
     *
     * @param context
     * @return
     */
    public static int getScreenHeight(Context context)
    {
        WindowManager wm = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(outMetrics);
        return outMetrics.heightPixels;
    }

    /**
     * 获得状态栏的高度
     *
     * @param context
     * @return
     */
    public static int getStatusHeight(Context context)
    {

        int statusHeight = -1;
        try
        {
            Class<?> clazz = Class.forName("com.android.internal.R$dimen");
            Object object = clazz.newInstance();
            int height = Integer.parseInt(clazz.getField("status_bar_height")
                    .get(object).toString());
            statusHeight = context.getResources().getDimensionPixelSize(height);
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        return statusHeight;
    }

    /**
     * 获取当前屏幕截图，包含状态栏
     *
     * @param activity
     * @return
     */
    public static Bitmap snapShotWithStatusBar(Activity activity)
    {
        View view = activity.getWindow().getDecorView();
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap bmp = view.getDrawingCache();
        int width = getScreenWidth(activity);
        int height = getScreenHeight(activity);
        Bitmap bp = null;
        bp = Bitmap.createBitmap(bmp, 0, 0, width, height);
        view.destroyDrawingCache();
        return bp;

    }

    /**
     * 获取当前屏幕截图，不包含状态栏
     *
     * @param activity
     * @return
     */
    public static Bitmap snapShotWithoutStatusBar(Activity activity)
    {
        View view = activity.getWindow().getDecorView();
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap bmp = view.getDrawingCache();
        Rect frame = new Rect();
        activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
        int statusBarHeight = frame.top;

        int width = getScreenWidth(activity);
        int height = getScreenHeight(activity);
        Bitmap bp = null;
        bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height
                - statusBarHeight);
        view.destroyDrawingCache();
        return bp;

    }

}

 

7、App相关辅助类

 

 

package com.zhy.utils;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;

/**
 * 跟App相关的辅助类
 *
 *
 *
 */
public class AppUtils
{

    private AppUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");

    }

    /**
     * 获取应用程序名称
     */
    public static String getAppName(Context context)
    {
        try
        {
            PackageManager packageManager = context.getPackageManager();
            PackageInfo packageInfo = packageManager.getPackageInfo(
                    context.getPackageName(), 0);
            int labelRes = packageInfo.applicationInfo.labelRes;
            return context.getResources().getString(labelRes);
        } catch (NameNotFoundException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * [获取应用程序版本名称信息]
     *
     * @param context
     * @return 当前应用的版本名称
     */
    public static String getVersionName(Context context)
    {
        try
        {
            PackageManager packageManager = context.getPackageManager();
            PackageInfo packageInfo = packageManager.getPackageInfo(
                    context.getPackageName(), 0);
            return packageInfo.versionName;

        } catch (NameNotFoundException e)
        {
            e.printStackTrace();
        }
        return null;
    }

}

 

8、软键盘相关辅助类KeyBoardUtils

 

 

package com.zhy.utils;

import android.content.Context;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;

/**
 * 打开或关闭软键盘
 *
 * @author zhy
 *
 */
public class KeyBoardUtils
{
    /**
     * 打卡软键盘
     *
     * @param mEditText
     *            输入框
     * @param mContext
     *            上下文
     */
    public static void openKeybord(EditText mEditText, Context mContext)
    {
        InputMethodManager imm = (InputMethodManager) mContext
                .getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(mEditText, InputMethodManager.RESULT_SHOWN);
        imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,
                InputMethodManager.HIDE_IMPLICIT_ONLY);
    }

    /**
     * 关闭软键盘
     *
     * @param mEditText
     *            输入框
     * @param mContext
     *            上下文
     */
    public static void closeKeybord(EditText mEditText, Context mContext)
    {
        InputMethodManager imm = (InputMethodManager) mContext
                .getSystemService(Context.INPUT_METHOD_SERVICE);

        imm.hideSoftInputFromWindow(mEditText.getWindowToken(), 0);
    }
}

 

9、网络相关辅助类 NetUtils

 

 

package com.zhy.utils;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

/**
 * 跟网络相关的工具类
 *
 *
 *
 */
public class NetUtils
{
    private NetUtils()
    {
        /* cannot be instantiated */
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * 判断网络是否连接
     *
     * @param context
     * @return
     */
    public static boolean isConnected(Context context)
    {

        ConnectivityManager connectivity = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        if (null != connectivity)
        {

            NetworkInfo info = connectivity.getActiveNetworkInfo();
            if (null != info && info.isConnected())
            {
                if (info.getState() == NetworkInfo.State.CONNECTED)
                {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * 判断是否是wifi连接
     */
    public static boolean isWifi(Context context)
    {
        ConnectivityManager cm = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        if (cm == null)
            return false;
        return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI;

    }

    /**
     * 打开网络设置界面
     */
    public static void openSetting(Activity activity)
    {
        Intent intent = new Intent("/");
        ComponentName cm = new ComponentName("com.android.settings",
                "com.android.settings.WirelessSettings");
        intent.setComponent(cm);
        intent.setAction("android.intent.action.VIEW");
        activity.startActivityForResult(intent, 0);
    }

}

 

 

10、Http相关辅助类 HttpUtils

package com.zhy.utils;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * Http请求的工具类
 *
 * @author zhy
 *
 */
public class HttpUtils
{

    private static final int TIMEOUT_IN_MILLIONS = 5000;

    public interface CallBack
    {
        void onRequestComplete(String result);
    }


    /**
     * 异步的Get请求
     *
     * @param urlStr
     * @param callBack
     */
    public static void doGetAsyn(final String urlStr, final CallBack callBack)
    {
        new Thread()
        {
            public void run()
            {
                try
                {
                    String result = doGet(urlStr);
                    if (callBack != null)
                    {
                        callBack.onRequestComplete(result);
                    }
                } catch (Exception e)
                {
                    e.printStackTrace();
                }

            };
        }.start();
    }

    /**
     * 异步的Post请求
     * @param urlStr
     * @param params
     * @param callBack
     * @throws Exception
     */
    public static void doPostAsyn(final String urlStr, final String params,
            final CallBack callBack) throws Exception
    {
        new Thread()
        {
            public void run()
            {
                try
                {
                    String result = doPost(urlStr, params);
                    if (callBack != null)
                    {
                        callBack.onRequestComplete(result);
                    }
                } catch (Exception e)
                {
                    e.printStackTrace();
                }

            };
        }.start();

    }

    /**
     * Get请求，获得返回数据
     *
     * @param urlStr
     * @return
     * @throws Exception
     */
    public static String doGet(String urlStr)
    {
        URL url = null;
        HttpURLConnection conn = null;
        InputStream is = null;
        ByteArrayOutputStream baos = null;
        try
        {
            url = new URL(urlStr);
            conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
            conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);
            conn.setRequestMethod("GET");
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            if (conn.getResponseCode() == 200)
            {
                is = conn.getInputStream();
                baos = new ByteArrayOutputStream();
                int len = -1;
                byte[] buf = new byte[128];

                while ((len = is.read(buf)) != -1)
                {
                    baos.write(buf, 0, len);
                }
                baos.flush();
                return baos.toString();
            } else
            {
                throw new RuntimeException(" responseCode is not 200 ... ");
            }

        } catch (Exception e)
        {
            e.printStackTrace();
        } finally
        {
            try
            {
                if (is != null)
                    is.close();
            } catch (IOException e)
            {
            }
            try
            {
                if (baos != null)
                    baos.close();
            } catch (IOException e)
            {
            }
            conn.disconnect();
        }

        return null ;

    }

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     * @throws Exception
     */
    public static String doPost(String url, String param)
    {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try
        {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            HttpURLConnection conn = (HttpURLConnection) realUrl
                    .openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            conn.setRequestProperty("charset", "utf-8");
            conn.setUseCaches(false);
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
            conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);

            if (param != null && !param.trim().equals(""))
            {
                // 获取URLConnection对象对应的输出流
                out = new PrintWriter(conn.getOutputStream());
                // 发送请求参数
                out.print(param);
                // flush输出流的缓冲
                out.flush();
            }
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null)
            {
                result += line;
            }
        } catch (Exception e)
        {
            e.printStackTrace();
        }
        // 使用finally块来关闭输出流、输入流
        finally
        {
            try
            {
                if (out != null)
                {
                    out.close();
                }
                if (in != null)
                {
                    in.close();
                }
            } catch (IOException ex)
            {
                ex.printStackTrace();
            }
        }
        return result;
    }
}

如果大家在使用过程中出现什么错误，或者有更好的建议，欢迎大家留言提出~~可以不断的改进这些类~