JSON字符串转javabean，MorphDynaBean cannot be cast to ……

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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 implements java.io.Serializable{/** * @Fields serialVersionUID : TODO*/ private static final long serialVersionUID = -1943961352036134112L;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;/** * * <P>Tiltle: AnalysisModel.java </P>* <P>Description:模型类  </P>* @author biyutong* @date Jun 11, 2012 9:37:54 AM * @version:V1.0 */public class AnalysisModel implements java.io.Serializable{/** * 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);

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