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

  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);