什么是Jackson
可以轻松实现Java对象与JSON字符串的转换
准备工作:导包
Jackson的jar all下载地址:http://jackson.codehaus.org/1.7.6/jackson-all-1.7.6.jar
1.实体对象转JSON
jackson使用getter方法定位属性(而不是字段)
可以通过添加注解 @JsonIgnore 使某些getter来进行忽略
将对象或集合转为json字符串
package cn.jackson; import java.io.IOException; import java.util.Arrays; import java.util.List; import org.codehaus.jackson.JsonGenerationException; import org.codehaus.jackson.annotate.JsonIgnore; import org.codehaus.jackson.map.JsonMappingException; import org.codehaus.jackson.map.ObjectMapper; public class Customer { private String name; private String id; public Customer() { super(); } public Customer(String name, String id) { super(); this.name = name; this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getId() { return id; } public void setId(String id) { this.id = id; } @JsonIgnore public String getCity(){ return "北京"; } public String getBirth(){ return "1988"; } public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException { //导包 //创建ObjectMapper对象 ObjectMapper mapper = new ObjectMapper(); // Customer cust = new Customer("jackson", "1001"); String jsonStr = mapper.writeValueAsString(cust); System.out.println(jsonStr); List<Customer> list = (List) Arrays.asList(cust,new Customer("33","离魂计")); String jsonStrList = mapper.writeValueAsString(list); System.out.println(jsonStrList); /** * jackson使用getter方法定位属性 * 可以通过添加注解 @JsonIgnore 使某些getter来进行忽略 */ } }
结果:
{"name":"jackson","id":"1001","birth":"1988"} [{"name":"jackson","id":"1001","birth":"1988"},{"name":"33","id":"离魂计","birth":"1988"}]
于是ajax_day02可以转为使用Jackson简化:
ObjectMapper mapper=new ObjectMapper(); String result=mapper.writeValueAsString(sc);
2.JSON字符串转对象
ObjectMapper mapper = new ObjectMapper(); String json = "{\"name\":\"jackson\",\"id\":\"1001\"}"; Customer c = mapper.readValue(json, Customer.class); System.out.println(c.getId());
//注意"的转义操作
时间: 2024-10-12 12:18:40