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前后端分离式开发无需返回值跳转，直接使用response输出json数据
 这种开发方式减少了前后端开发者的冲突。

控制层：
 
public class ReportAction {
    private static final long serialVersionUID = 1L;
    private IReportService reportService;

    public ReportAction() {
        reportService = ServiceFactory.getReportInstance();
    }

    public void getReportJson() {
        String jsonResult = reportService.getReportByDeptno();
        System.out.println(jsonResult);
        try {
            PrintWriter out = ServletActionContext.getResponse().getWriter();
            out.println(jsonResult);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
Service业务层： 
@Overridepublic String getReportByDeptno() {
String jsonResult = null;
try {
List<Report> reportList = reportDao.getReportByDeptno();
//目标：通过GSON将该集合变成json格式的字符串，所谓结果
returnGson gson = new Gson();
jsonResult = gson.toJson(reportList, new TypeToken<List<Report>>(){}.getType());
} 
catch (Exception e) 
{
e.printStackTrace();
}
return jsonResult;
}