jackson框架解析json

Jackson解析的速度算是同类框架中最快的，同时也是Spring MVC中内置使用的解析方式。

准备工作：

下载jar包：http://jackson.codehaus.org/1.7.6/jackson-all-1.7.6.jar

这个jar包在我的Demo中已经包含了，可以直接下载Demo：http://download.csdn.net/detail/u012251822/6877943

并将jar包添加到libs中

package com.example.jacksontest;

import java.io.IOException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.type.TypeReference;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import com.example.jacksongtest.R;

public class MainActivity extends Activity {

	public static ObjectMapper objectMapper = new ObjectMapper();

	private TextView mBeanTextView;
	private TextView mBeanListTextView;
	private TextView mBeanMapTextView;
	private TextView mBeanMapListTextView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		mBeanTextView = (TextView) findViewById(R.id.showBean);
		mBeanListTextView = (TextView) findViewById(R.id.showList);
		mBeanMapTextView = (TextView) findViewById(R.id.showMap);
		mBeanMapListTextView = (TextView) findViewById(R.id.showMapList);
		readJsonBean();
		readJsonBeanInList();
		readJsonBeanInMap();
		readJsonBeanInMapInList();
	}

	/**
	 * 读取Bean类型json
	 */
	public void readJsonBean() {
		String json = "{\"userName\": \"a\",\"password\":\"c\"}";
		try {
			User user = objectMapper.readValue(json, User.class);
			mBeanTextView.setText(user.toString());
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 读取List<-Bean>类型json
	 */
	public void readJsonBeanInList() {
		String json = "[{\"userName\": \"a\",\"password\":\"c\"},{\"userName\": \"b\",\"password\":\"d\"}]";
		try {
			User[] users = objectMapper.readValue(json, User[].class);
			List<User> userList = Arrays.asList(users);
			StringBuffer result = new StringBuffer();
			for (int i = 0; i < userList.size(); i++) {
				result.append(userList.get(i).toString() + "\t");
			}
			mBeanListTextView.setText(result);
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 读取Map<-Bean>类型json
	 */
	public void readJsonBeanInMap() {
		String json = "{\"A\":{\"userName\": \"a\",\"password\":\"c\"},"
				+ "\"B\":{\"userName\":\"b\",\"password\":\"d\"}}";
		ObjectMapper objectMapper = new ObjectMapper();
		try {
			Map<String, User> users = objectMapper.readValue(json,
					new TypeReference<Map<String, User>>() {
					});
			Set<String> keys = users.keySet();
			StringBuffer result = new StringBuffer();
			for (Iterator<String> it = keys.iterator(); it.hasNext();) {
				result.append(users.get(it.next()).toString() + "\t");
			}
			mBeanMapTextView.setText(result);
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 读取List<-Map<-String,Bean>>类型json
	 */
	public void readJsonBeanInMapInList() {
		String json = "[{\"A\":{\"userName\": \"a\",\"password\":\"a\"},\"C\":{\"userName\": \"c\",\"password\":\"c\"}},"
				+ "{\"B\":{\"userName\":\"b\",\"password\":\"b\"}}]";
		ObjectMapper objectMapper = new ObjectMapper();
		try {
			List<Map<String, User>> users = objectMapper.readValue(json,
					new TypeReference<List<Map<String, User>>>() {
					});
			StringBuffer result = new StringBuffer();
			for (int i = 0; i < users.size(); i++) {
				Map<String, User> tempMap = users.get(i);
				Set<String> keys = tempMap.keySet();
				for (Iterator<String> it = keys.iterator(); it.hasNext();) {
					result.append(tempMap.get(it.next()).toString() + "\t");
				}
			}
			mBeanMapListTextView.setText(result);
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
     >

    <TextView
        android:id="@+id/showBeanTv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/bean" />
    
    <TextView
        android:id="@+id/showBean"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    
    <TextView
        android:id="@+id/showListTv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="@string/bean_list" />
    
     <TextView
        android:id="@+id/showList"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <TextView
        android:id="@+id/showMapTv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="@string/bean_map" />
    
     <TextView
        android:id="@+id/showMap"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <TextView
        android:id="@+id/showMapListTv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="@string/bean_map_list" />
    
     <TextView
        android:id="@+id/showMapList"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</LinearLayout>

Demo下载：http://download.csdn.net/detail/u012251822/6877943