使用gson-1.6.jar解析json

package com.example.mars_2900_json01;

import java.io.StringReader;
import java.lang.reflect.Type;
import java.util.Iterator;
import java.util.LinkedList;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;

public class JsonUtils {
public static void parseJson(String jsonData) {
try {
// 如果需要解析JSON数据，首要要生成一个JsonReader对象
//"[{\"name\":\"Michael\",\"age\":20},{\"name\":\"Mike\",\"age\":21}]"
JsonReader reader = new JsonReader(new StringReader(jsonData));
reader.beginArray();//开始解析数组
while (reader.hasNext()) {
reader.beginObject();//开始解析对象
while (reader.hasNext()) {
String tagName = reader.nextName();
if (tagName.equals("name")) {
System.out.println("name--->" + reader.nextString());
} else if (tagName.equals("age")) {
System.out.println("age--->" + reader.nextInt());
}
}
reader.endObject();
}
reader.endArray();
} catch (Exception e) {
e.printStackTrace();
}
}

public static void parseUserFromJson(String jsonData){
Gson gson = new Gson();
User user = gson.fromJson(jsonData, User.class);
System.out.println("name--->" + user.getName());
System.out.println("age---->" + user.getAge());
}

public static void parseUserListFromJson(String jsonData){
Type listType = new TypeToken<LinkedList<User>>(){}.getType();
Gson gson = new Gson();
LinkedList<User> users = gson.fromJson(jsonData, listType);
for (Iterator iterator = users.iterator(); iterator.hasNext();) {
User user = (User) iterator.next();
System.out.println("name--->" + user.getName());
System.out.println("age---->" + user.getAge());
}
}
}

package com.example.mars_2900_json01;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.os.Build;

public class MainActivity extends ActionBarActivity {
private String jsonData = "[{\"name\":\"Michael\",\"age\":20},{\"name\":\"Mike\",\"age\":21}]";
private String jsonData2 = "{\"name\":\"json\",\"age\":21}";
private Button button;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

button = (Button) findViewById(R.id.buttonId);
button.setOnClickListener(new ButtonListener());
}

private class ButtonListener implements OnClickListener {

@Override
public void onClick(View v) {
JsonUtils.parseJson(jsonData);
JsonUtils.parseUserFromJson(jsonData2);
JsonUtils.parseUserListFromJson(jsonData);

}

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}

/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {

public PlaceholderFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}

}