首先添加权限： <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
package org.lxh.demo;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String data [] = new String [] {"www.mldnjava.cn","lixinghua",
"bbs.mldn.cn"} ;
JSONObject allData = new JSONObject() ;//最外面的节点对象
JSONArray sing = new JSONArray() ;
for (int x = 0 ; x < data.length ; x++){
JSONObject temp = new JSONObject() ; //每一个包装的数据都是JSONObject
try {
temp.put("myurl",data[x]);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
sing.put(temp) ; //保存多个JSONObject
}
try {
allData.put("urldata", sing) ;
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(!Environment.getExternalStorageState()
.equals(Environment.MEDIA_MOUNTED)){
return ;
}
File file = new File(Environment.getExternalStorageDirectory()
+File.separator+"mldndata"+File.separator
+"json.txt") ;
if(!file.getParentFile().exists()){
file.getParentFile().mkdirs() ;
}
PrintStream out = null ;
try {
out = new PrintStream(new FileOutputStream(file));
out.print(allData.toString()) ;//将数据变为字符串后保存
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(out != null){
out.close() ;
}
}
}
}
导出sdcard中json.txt的数据：
{"urldata":[{"myurl":"www.mldnjava.cn"},{"myurl":"lixinghua"},{"myurl":"bbs.mldn.cn"}]}