一个json string和泛型对象转换的经典实例

<p>花了我三个多小时（java还需要努力啊）;</p>
<p>只有我自己看得懂，哈哈！！！！</p>
<p>/**elbert.chenh寫於2010年1月5日晚<br> * 实现如下功能<br> * 1.将用户传递的个性化的jsonstr队列转换为标准化的统一的jsonstr队列<br> *  如队列中的元素{/"taskId/":/"t01/",/"sceneId/":/"s01/",/"caseId/":/"cs01/",/"SYNOPSIS/":/"p1/",/"id/":1,/"cpu/":/"cpu01/"}<br> *  转化为标准化元素{/"taskId/":/"t01/",/"sceneId/":/"s01/",/"caseId/":/"cs01/",/"param1/":/"p1/",/"id/":1,/"param10/":/"cpu01/"}<br> * 2.将队列中的jsonstr转换为对应的类实例<br> * 3.调用插入数据库函数将结果插入数据库中<br> * @param jstrCaseLog<br> */<br>public void insertCaseLog(String jstrCaseLog)<br>{<br>List&lt;Object&gt; ls = com.alisoft.testplat.help.JsonFunc.fromJSON(<br>jstrCaseLog, ArrayList.class);<br>//取得数据库中所有的LogParam<br>TestCaseService tss = new TestCaseService();<br>List&lt;LogParam&gt; lp = tss.getLogParamList();<br>List&lt;LinkedHashMap&gt; lstmp = new ArrayList&lt;LinkedHashMap&gt;();<br>LinkedHashMap map = new LinkedHashMap();<br>for (int i = 0; i &lt; ls.size(); i++) {<br>map = (LinkedHashMap) ls.get(i);<br>for (int j = 0; j &lt; map.keySet().size(); j++) {<br>//使用Key去寻找是哪个Param，如果不是那么就返回自己<br>for(int k = 0; k &lt; lp.size(); k++)<br>{<br>LogParam tmplp = lp.get(k);<br>//如果传入的参数别名=某条记录的参数别名，那么替换为该参数实际名称<br>if(map.keySet().toArray()[j].toString().toLowerCase().equals(tmplp.getParamAlias().toLowerCase()))<br>{<br>Object value = map.get(map.keySet().toArray()[j]);<br>map.remove(map.keySet().toArray()[j]);<br>map.put(tmplp.getParamName().toLowerCase(), value);<br>}<br>}<br>}<br>lstmp.add(map);<br>}<br>String tempstr = com.alisoft.testplat.help.JsonFunc.toJSON(lstmp);<br>List&lt;Object&gt; deslp = com.alisoft.testplat.help.JsonFunc.fromJSON(tempstr, ArrayList.class);<br>for(int index = 0; index &lt; deslp.size(); index++)<br>{<br>String cp = getListNode(deslp,index);<br>CaseLog tlp = com.alisoft.testplat.help.JsonFunc.fromJSON(cp, CaseLog.class);<br>CaseLogDao.InsertCaseLog(tlp);<br>}<br>}<br><br>public String getListNode(List&lt;Object&gt; ls,int index)<br>{<br>StringBuilder desstr = new StringBuilder("{");<br>LinkedHashMap map = new LinkedHashMap();<br>map = (LinkedHashMap) ls.get(index);<br>for (int j = 0; j &lt; map.keySet().size(); j++) {<br>//如果传入的参数别名=某条记录的参数别名，那么替换为该参数实际名臣<br>Object key =map.keySet().toArray()[j];<br>Object value = map.get(map.keySet().toArray()[j]);<br>if(j &lt; (map.keySet().size()-1))<br>{<br>if (value != null)<br>{<br>desstr.append("/"").append(key.toString()).append("/":").append("/"").append(value.toString()).append("/"").append(",");<br>}<br>else<br>{<br>desstr.append("/"").append(key.toString()).append("/":").append("null").append(",");<br>}<br>}<br>else<br>{ <br>if (value != null)<br>{<br>desstr.append("/"").append(key.toString()).append("/":").append("/"").append(value.toString()).append("/"").append("}");<br>}<br>else<br>{<br>desstr.append("/"").append(key.toString()).append("/":").append("null").append("}");<br>}<br>}<br>}</p>
<p>System.out.println(desstr.toString());<br>return desstr.toString();<br>}</p>
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<p>public static String toJSON(Object obj) {<br> StringWriter writer = new StringWriter();<br> try {<br> mapper.writeValue(writer, obj);<br> } catch (JsonGenerationException e) {<br> throw new RuntimeException(e);<br> } catch (JsonMappingException e) {<br> throw new RuntimeException(e);<br> } catch (IOException e) {<br> throw new RuntimeException(e);<br> }<br> return writer.toString();<br>}<br><br>public static &lt;T&gt; T fromJSON(String json, Class&lt;T&gt; clazz) {<br> ObjectMapper mapper = new ObjectMapper();<br> try {<br> return mapper.readValue(json, clazz);<br> } catch (JsonParseException e) {<br> throw new RuntimeException(e);<br> } catch (JsonMappingException e) {<br> throw new RuntimeException(e);<br> } catch (IOException e) {<br> throw new RuntimeException(e);<br> }<br> }</p>