json <--->List集合,实体类 之间的相互转换

json所依赖的jar包http://files.VEVb.com/files/wenjie123/json_jar%E5%8C%85.rarpackage com.hp.svse;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;import net.sf.json.JsonConfig;import net.sf.json.PRocessors.JsonValueProcessor;/** * Timestamp 处理器 */public class JsonDateValueProcessor implements JsonValueProcessor {    private String formatDateTime ="yyyy-MM-dd HH:mm:ss";    private String formatDate ="yyyy-MM-dd";    public Object processArrayValue(Object value, JsonConfig config) {        return process(value);    }    public Object processObjectValue(String key, Object value, JsonConfig config) {        return process(value);    }        private Object process(Object value){                if(value instanceof Date){            SimpleDateFormat sdf ;            if(value.toString().length()<=11||value.toString().indexOf("00:00:00.0")>=0){                sdf= new SimpleDateFormat(formatDate,Locale.UK);            }else{                sdf= new SimpleDateFormat(formatDateTime,Locale.UK);            }            return sdf.format(value);        }        return value == null ? "" : value.toString();    }}

package com.hp.svse;import java.util.ArrayList;import java.util.Date;import java.util.List;import net.sf.json.JSONArray;import net.sf.json.JSONObject;import net.sf.json.JsonConfig;public class JsonTest {    public static void main(String[] args) {                /**         * 将对象集合转换成JSON格式的字符串         */        List<Student> students = new ArrayList<Student>();        students.add(new Student("小明1", "男", "湖北", "SVSE"));        students.add(new Student("小明2", "女", "广东", "GIS"));        students.add(new Student("小明3", "男", "香港", "3G"));        JsonTest jsonTest = new JsonTest();        String json = jsonTest.beanListToJSON(students);        System.out.println(json);        /**         * 输出结果：         * [         *     {"sex":"男","address":"湖北","stuname":"小明1","classname":"SVSE","smallStudents":[]},         *     {"sex":"女","address":"广东","stuname":"小明2","classname":"GIS","smallStudents":[]},         *     {"sex":"男","address":"香港","stuname":"小明3","classname":"3G","smallStudents":[]}         * ]         */                                                /**         * 将json字符串转换成json对象  再讲json对象转换成实体对象bean         */        String bookCotentjsonStr = "{/"sex/":/"男/",/"address/":/"湖北/",/"stuname/":/"小明1/",/"classname/":/"SVSE/"}";        JSONObject bookCotentjson = JSONObject.fromObject(bookCotentjsonStr);        Student student = (Student) JSONObject.toBean(bookCotentjson, Student.class);        System.out.println(student);        /**         * 输出结果：Student [address=湖北, classname=SVSE, sex=男, stuname=小明1]         */                                        /**         * 将对象转换成JSON格式的字符串 适用于单个对象(单个对象里可以包含List<T>)的转换         */        List<SmallStudent> smallStudents = new ArrayList<SmallStudent>();        for (int i = 0; i < 3; i++) {            SmallStudent smallStudent = new SmallStudent();            smallStudent.setName("小学生"+i);            smallStudent.setAge("1"+i);            smallStudents.add(smallStudent);        }        Student student2 = new Student("小明", "男", "武汉", "svse",smallStudents);        String jsonStr = jsonTest.beanToJSON(student2);        System.out.println(jsonStr);        /**         * 输出结果：         * {"sex":"男","address":"武汉","stuname":"小明","classname":"svse","smallStudents":[{"sex":"","age":"10","name":"小学生0"},{"sex":"","age":"11","name":"小学生1"},{"sex":"","age":"12","name":"小学生2"}]}         */                            }    /**     * 将集合转换成JSON格式的字符串     */    public <T> String beanListToJSON(List<T> t) {        String json = "";        JsonConfig jsonConfig = new JsonConfig();        jsonConfig.registerJsonValueProcessor(Date.class,                new JsonDateValueProcessor());        if(t!=null){        json = JSONArray.fromObject(t, jsonConfig).toString();        }else{            json="[]";        }        return json;    }        /**     * 将对象转换成JSON格式的字符串 适用于单个对象(单个对象里可以包含List<T>)的转换     */    public <T> String beanToJSON(T t) {        String json = "";        JsonConfig jsonConfig = new JsonConfig();        jsonConfig.registerJsonValueProcessor(Date.class,                new JsonDateValueProcessor());        if(t!=null){        json = JSONObject.fromObject(t, jsonConfig).toString();        }else{            json="[]";        }        return json;    }}

package com.hp.svse;import java.util.List;public class Student {    private String stuname;    private String sex;    private String address;    private String classname;    private List<SmallStudent> smallStudents;        public Student(String stuname, String sex, String address, String classname,List<SmallStudent> smallStudents) {        super();        this.stuname = stuname;        this.sex = sex;        this.address = address;        this.classname = classname;        this.smallStudents = smallStudents;    }    public Student(String stuname, String sex, String address, String classname) {        super();        this.stuname = stuname;        this.sex = sex;        this.address = address;        this.classname = classname;    }    public Student() {        super();    }    public String getStuname() {        return stuname;    }    public void setStuname(String stuname) {        this.stuname = stuname;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    public String getAddress() {        return address;    }    public void setAddress(String address) {        this.address = address;    }    public String getClassname() {        return classname;    }    public void setClassname(String classname) {        this.classname = classname;    }    public List<SmallStudent> getSmallStudents() {        return smallStudents;    }    public void setSmallStudents(List<SmallStudent> smallStudents) {        this.smallStudents = smallStudents;    }    @Override    public String toString() {        return "Student [address=" + address + ", classname=" + classname                + ", sex=" + sex + ", stuname=" + stuname + "]";    }    }

package com.hp.svse;public class SmallStudent {    private String name;    private String age;    private String sex;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getAge() {        return age;    }    public void setAge(String age) {        this.age = age;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    @Override    public String toString() {        return "SmallStudent [age=" + age + ", name=" + name + ", sex=" + sex                + "]";    }}