json-lib之复杂数据类型的转换

在json字符串转java bean时，一般的对象，可以直接转，如：一个学生类，属性有姓名、年龄等

    public class Student{  

        private String sname;
        private Integer age;
        public String getSname() {
            return sname;
        }
        public void setSname(String sname) {
            this.sname = sname;
        }
        public Integer getAge() {
            return age;
        }
        public void setAge(Integer age) {
            this.age = age;
        }  

    }  

由字符串转java bean时可以使用以下方法：

    JSONObject jobj = JSONObject.fromObject(str);
    Student s = (Student) JSONObject.tobean(jobj，Student.class);  

是没有问题的，但是如果属性中含有复杂的类型，当其中属性有类似List , Map ,ArrayList、自定义的类型，如List<Teacher> teachers, 就不可以了。 会报错：MorphDynaBean cannot be cast to con.test……

在JSONObject.toBean的时候如果转换的类中有集合,可以先定义Map<String, Class> classMap = new HashMap<String, Class>();在classMap中put你要转换的类中的集合名,像:classMap.put("teachers", Teacher.class);然后在toBean()的时候把参数加上, 像:Student student=(Student) JSONObject.toBean(str, Student.class, classMap);

比如我定义了如下类型：

    import java.util.List;  

    public class AnalysisModel{  

        /**
         * 固定条件
         */
        private List<Condition> regularCondtionList;//
        /**
         * 动态条件
         */
        private List<ConditionField> dynamicConFieldList;
        /**
         * 结果
         */
        private List<ResultField> resultField;
        /**
         * 获取前多少条数据
         */
        private Integer topnum;
        /**
         * 顺序还是随机
         */
        private String sortFlag;
        /**
         * 备注
         */
        private String remark;
        /**
         * 模型名称
         */
        private String modelName;
        /**
         * 对应的xml文件名称
         */
        private String fileName;
        public List<Condition> getRegularCondtionList() {
            return regularCondtionList;
        }
        public void setRegularCondtionList(List<Condition> regularCondtionList) {
            this.regularCondtionList = regularCondtionList;
        }
        public List<ConditionField> getDynamicConFieldList() {
            return dynamicConFieldList;
        }
        public void setDynamicConFieldList(List<ConditionField> dynamicConFieldList) {
            this.dynamicConFieldList = dynamicConFieldList;
        }
        public Integer getTopnum() {
            return topnum;
        }
        public void setTopnum(Integer topnum) {
            this.topnum = topnum;
        }
        public String getSortFlag() {
            return sortFlag;
        }
        public void setSortFlag(String sortFlag) {
            this.sortFlag = sortFlag;
        }
        public String getRemark() {
            return remark;
        }
        public void setRemark(String remark) {
            this.remark = remark;
        }  

        public String getModelName() {
            return modelName;
        }
        public void setModelName(String modelName) {
            this.modelName = modelName;
        }
        public List<ResultField> getResultField() {
            return resultField;
        }
        public void setResultField(List<ResultField> resultField) {
            this.resultField = resultField;
        }
        public String getFileName() {
            return fileName;
        }
        public void setFileName(String fileName) {
            this.fileName = fileName;
        }  

    }  

在转化的时候需要这样来写：

    Map<String, Class> classMap = new HashMap<String, Class>();  

    classMap.put("regularCondtionList", Condition.class);  

    classMap.put("dynamicConFieldList", ConditionField.class);  

    classMap.put("resultField", ResultField.class);  

    AnalysisModel analysisModel=(AnalysisModel) JSONObject.toBean(str, AnalysisModel.class, classMap);