json-lib出现There is a cycle in the hierarchy解决办法

如果需要解析的数据间存在级联关系，而互相嵌套引用，在hibernate中极容易嵌套而抛出net.sf.json.JSONException: There is a cycle in the hierarchy异常。

解决办法

1.设置JSON-LIB让其过滤掉引起循环的字段。

Java代码

 
JsonConfig config = new JsonConfig(); 
config.setIgnoreDefaultExcludes(false); 
config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT); 
config.registerJsonValueProcessor(Date.class,new DateJsonValueProcessor("yyyy-MM-dd")); //date processor register 
config.setExcludes(new String[]{//只要设置这个数组，指定过滤哪些字段。 
"consignee", 
"contract", 
"coalInfo", 
"coalType", 
"startStation", 
"balanceMan", 
"endStation" 
}); 
String tempStr = "{\"TotalRecords\":"+ total.toString() +",\"Datas\":"+JSONSerializer.toJSON(list,config).toString()+"}"; 
out.print(tempStr); 
JsonConfig config = new JsonConfig(); 
config.setIgnoreDefaultExcludes(false); 
config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT); 
config.registerJsonValueProcessor(Date.class,new DateJsonValueProcessor("yyyy-MM-dd")); //date processor register 
config.setExcludes(new String[]{//只要设置这个数组，指定过滤哪些字段。 "consignee", "contract", "coalInfo", "coalType", "startStation", "balanceMan", "endStation" }); String tempStr = "{\"TotalRecords\":"+ total.toString() +",\"Datas\":"+JSONSerializer.toJSON(list,config).toString()+"}"; out.print(tempStr); 

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。 
Java代码 
[code] 
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); 