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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
复制代码 代码如下:
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);
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发表于 2010-2-24 19:17:41
