使用jackson工具类把对象或集合转为JSON格式

jackson使用方法：

1、加入jar包：

jackson-annotations-2.2.2.jar

jackson-core-2.2.2.jar

jackson-databind-2.2.2.jar

2、具体的使用步骤：

1）、创建org.codehaus.jackson,map.ObjectMapper 对象

2）、调用ObjectMapper 的 writeValueAsString 方法把Java 对象或集合转为JSON字符串

ObjectMapper mapper = new ObjectMapper();

String jsonStr = mapper.writerValueAsString(String str);

3、注意：

1）、Jackson 根据getter 来定位Json 对象的属性，而不是字段！

2）、可以在类的 getter 方法上添加注解：org.codehaus.jackson.annotate.JsonIgnore . 转为Json对象时已忽略该属性！

测试代码如下：

package com.lym.ajax.beans;

import java.util.Arrays;
import java.util.List;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * jackson测试类
 * @author liuyanmin
 * 2015-1-20 上午11:23:55
 */
public class ShopCart {

private String bookName;
private int price=0;
private int number=0;



public ShopCart(String bookName, int price, int number) {
super();
this.bookName = bookName;
this.price = price;
this.number = number;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
@JsonIgnore
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
public int getNumber() {
return number;
}
public void setNumber(int number) {
this.number = number;
}

public static void main(String args[]){

ObjectMapper mapper = new ObjectMapper();

ShopCart sc = new ShopCart("JavaEE",100,1);
List<ShopCart> list = Arrays.asList(sc,new ShopCart("Oracle",200,2));

try {
String result = mapper.writeValueAsString(sc);
String resList = mapper.writeValueAsString(list);
System.out.println(result);
System.out.println(resList);
} catch (JsonProcessingException e) {
e.printStackTrace();
}

}
}