struts1+json的应用

struts1不像struts2一样，并未对json做集成，因此要使用json就必须自己写代码实现json对象的封装，可以在BaseAction中写一个共通方法，用于封装后台的数据为json对象并发送到前台：

public class BaseAction extends Action{private String encoding = "UTF-8";private String contentType = "application/json";/** * to make JSON object that will be returned to the front-end and send it *  * @param response response * @param objName jsonObjectName * @param obj object that is used to make jsonObject * @throws IOException */protected void makeJSONObject(HttpServletResponse response, String objName, Object obj) throws IOException {this.contentType = contentType + ";charset=" + encoding;LogUtil.log.info("Set contentType to: " + contentType);JSONObject jsonObj = new JSONObject();jsonObj.put(objName, obj);response.setContentType(contentType);response.setCharacterEncoding(encoding);PrintWriter pw = response.getWriter(); pw.write(jsonObj.toString());pw.flush();}}

action中调用该方法就可以发送json数据了，但是要保证传入的obj是能够序列化的，因此，一般来说需要事先做一些处理，最好的方法当然就是大家都熟悉的bean了：

public class SearchEnToCnAction extends BaseAction {// 使用普遍依赖注入方式private SearchEnToCnBean searchEnToCnBean;@Overridepublic ActionForward execute(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception {                // 取得前台的Ajax数据String searchStr = request.getParameter("searchStr");List<Object[]> enWordInfo = searchEnToCnBean.searchEnToCn(searchStr);if (enWordInfo.isEmpty()) {Map<String, Object> jsonResponseLs = new HashMap<String, Object>();jsonResponseLs.put("enWordInfo", null);super.makeJSONObject(response, "enWordResponse", jsonResponseLs);} else {// json process for EnWordList<EnWordVo> jsonEnWordLs = new ArrayList<EnWordVo>();EnWordVo jsonEnWord;for (int i = 0; i < enWordInfo.size(); i ++) {Object[] enWord = enWordInfo.get(i);jsonEnWord = new EnWordVo(enWord[0], enWord[1], enWord[2],enWord[3], enWord[4], enWord[5], enWord[6], enWord[7],enWord[8], enWord[9], enWord[10]);jsonEnWordLs.add(jsonEnWord);}// json process for EnExtdWordList<Object[]> enExtdWordInfo = searchEnToCnBean.searchEnToCnExtdInfo(searchStr);List<EnExtdWordVo> jsonEnExtdWordLs = new ArrayList<EnExtdWordVo>();if (enExtdWordInfo.isEmpty()) {jsonEnExtdWordLs = null;} else {EnExtdWordVo jsonEnExtdWord;for (int i = 0; i < enExtdWordInfo.size(); i ++) {Object[] enExtdWord = enExtdWordInfo.get(i);jsonEnExtdWord = new EnExtdWordVo(enExtdWord[0], enExtdWord[1], enExtdWord[2],enExtdWord[3], enExtdWord[4], enExtdWord[5], enExtdWord[6], enExtdWord[7],enExtdWord[8], enExtdWord[9], enExtdWord[10], enExtdWord[11]);jsonEnExtdWordLs.add(jsonEnExtdWord);}}Map<String, Object> jsonResponseLs = new HashMap<String, Object>();jsonResponseLs.put("enWordInfo", jsonEnWordLs);jsonResponseLs.put("enExtdWordInfo", jsonEnExtdWordLs);super.makeJSONObject(response, "enWordResponse", jsonResponseLs);}return (mapping.findForward(null));}public void setSearchEnToCnBean(SearchEnToCnBean searchEnToCnBean) {this.searchEnToCnBean = searchEnToCnBean;}public SearchEnToCnBean getSearchEnToCnBean() {return searchEnToCnBean;}}

上面所使用的两个VO很简单：

public class EnWordVo {private Object word;private Object extdAttr;private Object mean;private Object dictId;private Object wordId;private Object partOfSpeech;private Object meaningNum;private Object exampleNum;private Object exampleExtdAttr;private Object enExmp;private Object exmpMeaning;public EnWordVo(Object word, Object extdAttr, Object mean, Object dictId,Object wordId, Object partOfSpeech, Object meaningNum,Object exampleNum, Object exampleExtdAttr, Object enExmp,Object exmpMeaning) {super();this.word = word;this.extdAttr = extdAttr;this.mean = mean;this.dictId = dictId;this.wordId = wordId;this.partOfSpeech = partOfSpeech;this.meaningNum = meaningNum;this.exampleNum = exampleNum;this.exampleExtdAttr = exampleExtdAttr;this.enExmp = enExmp;this.exmpMeaning = exmpMeaning;}public Object getWord() {return word;}public void setWord(String word) {this.word = word;}public Object getExtdAttr() {return extdAttr;}public void setExtdAttr(String extdAttr) {this.extdAttr = extdAttr;}public Object getMean() {return mean;}public void setMean(String mean) {this.mean = mean;}public Object getDictId() {return dictId;}public void setDictId(String dictId) {this.dictId = dictId;}public Object getWordId() {return wordId;}public void setWordId(String wordId) {this.wordId = wordId;}public Object getPartOfSpeech() {return partOfSpeech;}public void setPartOfSpeech(String partOfSpeech) {this.partOfSpeech = partOfSpeech;}public Object getMeaningNum() {return meaningNum;}public void setMeaningNum(String meaningNum) {this.meaningNum = meaningNum;}public Object getExampleNum() {return exampleNum;}public void setExampleNum(String exampleNum) {this.exampleNum = exampleNum;}public Object getExampleExtdAttr() {return exampleExtdAttr;}public void setExampleExtdAttr(String exampleExtdAttr) {this.exampleExtdAttr = exampleExtdAttr;}public Object getEnExmp() {return enExmp;}public void setEnExmp(String enExmp) {this.enExmp = enExmp;}public Object getExmpMeaning() {return exmpMeaning;}public void setExmpMeaning(String exmpMeaning) {this.exmpMeaning = exmpMeaning;}}