关于安卓复制/data/data文件的问题

囧蜀黍 2013-09-26 11:52:51

想要复制在/data/data目录下的某个文件，却出现错误，原代码如下:

package com.jiong.copyma;



import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;



import android.os.Bundle;

import android.os.Environment;

import android.app.Activity;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;



public class MainActivity extends Activity {



	private Button m_btn1;

	private final static String FROMPATH = "data/data/com.square_enix.ss/files/dt.txt";

	private final static String TOPATH = "data/data/com.square_enix.ss/";



	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		upgradeRootPermission(getPackageCodePath());

		m_btn1 = (Button) findViewById(R.id.account1);

		// m_btn2 = (Button)findViewById(R.id.account2);

		m_btn1.setOnClickListener(new OnClickListener() {



			@Override

			public void onClick(View arg0) {

				// TODO Auto-generated method stub

				Log.e("11", "3333333");

				if (copy(FROMPATH, TOPATH) == 0) {

					Toast.makeText(MainActivity.this, "文件拷贝成功！！！", 20000)

							.show();



				} else {

					Toast.makeText(MainActivity.this, "文件拷贝失败！！！", 20000)

							.show();

				}

			}



		});

	}



	public static boolean upgradeRootPermission(String pkgCodePath) { 

	    Process process = null; 

	    DataOutputStream os = null; 

	    try { 

	        String cmd="chmod 777 " + "data/data/com.square_enix.ss/files/dt.txt"; 

	        process = Runtime.getRuntime().exec("su"); //切换到root帐号 

	        os = new DataOutputStream(process.getOutputStream()); 

	        os.writeBytes(cmd + "\n"); 

	        os.writeBytes("exit\n"); 

	        os.flush(); 

	        process.waitFor(); 

	    } catch (Exception e) { 

	        return false; 

	    } finally { 

	        try { 

	            if (os != null) { 

	                os.close(); 

	            } 

	            process.destroy(); 

	        } catch (Exception e) { 

	        } 

	    } 

	    return true; 

	} 

	

	 public int copy(String fromFile, String toFile)

	    {

	        //要复制的文件目录

	        File[] currentFiles;

	        File root = new File(fromFile);

	        //如同判断SD卡是否存在或者文件是否存在

	        //如果不存在则 return出去

	        if(!root.exists())

	        {

	            return -1;

	        }

	        //如果存在则获取当前目录下的全部文件 填充数组

	        currentFiles = root.listFiles();

	         

	        //目标目录

	        File targetDir = new File(toFile);

	        //创建目录

	        if(!targetDir.exists())

	        {

	            targetDir.mkdirs();

	        }

	        //遍历要复制该目录下的全部文件

	        for(int i= 0;i<currentFiles.length;i++)

	        {

	            if(currentFiles[i].isDirectory())//如果当前项为子目录 进行递归

	            {

	                copy(currentFiles[i].getPath() + "/", toFile + currentFiles[i].getName() + "/");

	                 

	            }else//如果当前项为文件则进行文件拷贝

	            {

	                CopyFile(currentFiles[i].getPath(), toFile + currentFiles[i].getName());

	            }

	        }

	        return 0;

	    }

	     



	// 文件拷贝

	// 要复制的目录下的所有非子目录(文件夹)文件拷贝

	public int CopyFile(String fromFile, String toFile) {

		

		

		Log.e("11", "22222");

		//File in = new File(fromFile);

		//File out = new File(toFile);

		Log.e("11", "555555");

		try {

			Log.e("11", "6666666");

			//FileInputStream fosfrom = new FileInputStream(in);

			//FileOutputStream fosto = new FileOutputStream(out);

			InputStream fosfrom = new FileInputStream(fromFile);

			OutputStream fosto = new FileOutputStream(toFile);

			byte bt[] = new byte[1024];

			Log.e("11", "44444");

			int c;

			while ((c = fosfrom.read(bt)) > 0) {

				fosto.write(bt, 0, c);

			}

			fosfrom.close();

			fosto.close();

			return 0;



		} catch (Exception ex) {

			ex.printStackTrace();

			return -1;

		}



	}



}

错误提示：

09-26 23:44:09.520: E/11(11363): 3333333

09-26 23:44:09.520: E/AndroidRuntime(11363): FATAL EXCEPTION: main

09-26 23:44:09.520: E/AndroidRuntime(11363): java.lang.NullPointerException

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at com.jiong.copyma.MainActivity.copy(MainActivity.java:103)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at com.jiong.copyma.MainActivity$1.onClick(MainActivity.java:43)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.view.View.performClick(View.java:4171)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.view.View$PerformClick.run(View.java:17070)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.os.Handler.handleCallback(Handler.java:615)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.os.Handler.dispatchMessage(Handler.java:92)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.os.Looper.loop(Looper.java:137)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at android.app.ActivityThread.main(ActivityThread.java:4797)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at java.lang.reflect.Method.invokeNative(Native Method)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at java.lang.reflect.Method.invoke(Method.java:511)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)

09-26 23:44:09.520: E/AndroidRuntime(11363): 	at dalvik.system.NativeStart.main(Native Method)