There is a cycle in the hierarchy解决办法

http://www.diybl.com/course/1_web/javascript/jsjs/20090415/165099.html

property 'delegate' has no getter method异常参考: http://panyongzheng.iteye.com/blog/1492278

解决办法

1.设置JSON-LIB让其过滤掉引起循环的字段。这个比较能解决问题，第2种方式只排除一个类，但是Hibernate会用到很多类，很难排除所有。

		JsonConfig config = new JsonConfig();  
        config.setIgnoreDefaultExcludes(false);  
        config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);  
        config.registerJsonValueProcessor(Date.class, new DateJsonValueProcessor("yyyy-MM-dd"));   
        config.setExcludes(new String[] {// 只要设置这个数组，指定过滤哪些字段。  
        "ctuAcademicStaffCcs",   
        "ctuProjects"});  
        System.out.println(JSONSerializer.toJSON(list, config).toString());

2.设置JSON-LIB的setCycleDetectionStrategy属性让其自己处理循环，省事但是数据过于复杂的话会引起数据溢出或者效率低下。

JsonConfig config = new JsonConfig();
		config.setIgnoreDefaultExcludes(false);
		config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);
		config.registerJsonValueProcessor(Date.class, new DateJsonValueProcessor("yyyy-MM-dd")); 
		// date processor
		// register
		String tempStr = "{\"TotalRecords\":" + total.toString() + ",\"Datas\":" + JSONSerializer.toJSON(list, config).toString() + "}";
		out.print(tempStr);

--------------------------------------------------------
一下是用到的三个类:

package com.common;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;

public class DateJsonValueProcessor implements JsonValueProcessor {
	public static final String Default_DATE_PATTERN = "yyyy-MM-dd";
	private DateFormat dateFormat;

	public DateJsonValueProcessor(String datePattern) {
		try {
			dateFormat = new SimpleDateFormat(datePattern);

		} catch (Exception e) {
			dateFormat = new SimpleDateFormat(Default_DATE_PATTERN);

		}

	}

	public Object processArrayValue(Object value, JsonConfig jsonConfig) {
		return process(value);
	}

	public Object processObjectValue(String key, Object value,
			JsonConfig jsonConfig) {
		return process(value);
	}

	private Object process(Object value) {
		return dateFormat.format((Date) value);

	}
}

package com.common;

import net.sf.json.JSONObject;
import net.sf.json.JsonConfig;
import net.sf.json.processors.*;

public class HibernateJsonBeanProcessor implements JsonBeanProcessor {
	public JSONObject processBean(Object obj, JsonConfig jsonConfig) {
		return new JSONObject();
	}
}

package com.common;

import net.sf.json.processors.*;    
import java.util.Set;    
import org.apache.log4j.Logger;    
    
public class HibernateJsonBeanProcessorMatcher extends JsonBeanProcessorMatcher {    
    private static Logger log = Logger    
        .getLogger(HibernateJsonBeanProcessorMatcher.class);    
    
	@Override
	public Object getMatch(Class target, Set set) {
		System.out.println("@target.getName()="+target.getName());
		if (target.getName().contains("$$EnhancerByCGLIB$$")) {
			log.warn("Found Lazy-References in Hibernate object " + target.getName());
			return org.hibernate.proxy.HibernateProxy.class;
		}
		return DEFAULT.getMatch(target, set);
	}  
}