今天才知道struts还有Preparable接口，实现此接口需要实现其prepare()方法，调用action中其他方法之前会先调用prepare()方法。此接口和方法可以用于初始化一些数据。

 

测试代码:

package cn.qlq.action;import org.apache.struts2.convention.annotation.Action;import org.apache.struts2.convention.annotation.Namespace;import org.apache.struts2.convention.annotation.ParentPackage;import org.apache.struts2.convention.annotation.Result;import com.opensymphony.xwork2.ActionSupport;import com.opensymphony.xwork2.Preparable;@Namespace("/")@ParentPackage("default")public class FirstAction extends ActionSupport implements Preparable {    private static final long serialVersionUID = 1L;    private String test;    @Override    public void prepare() throws Exception {        System.out.println("这是所有方法前的处理");    }    @Action(value = "test",             results = { @Result(name = "success1", location = "/index2.jsp", type = "redirect") ,                        @Result(name = "error", location = "/index2.jsp") ,                        @Result(name = "success" ,type = "json" , params = {"root","test"})                         })    @Override    public String execute() throws Exception {        test = "test";        return super.execute();    }    public String getTest() {        return test;    }    public void setTest(String test) {        this.test = test;    }    }

 

 

当我们访问execute方法的时候会先执行prepare()方法。

 

 

　　另外，当action种有一个方法叫做haha(),我们可以定义一个prepareHaha()方法，则在访问haha()之前会先访问prepareHaha()，再访问prepare()，最后访问haha(),如下代码:

package cn.qlq.action;import org.apache.struts2.convention.annotation.Action;import org.apache.struts2.convention.annotation.Namespace;import org.apache.struts2.convention.annotation.ParentPackage;import org.apache.struts2.convention.annotation.Result;import com.opensymphony.xwork2.ActionSupport;import com.opensymphony.xwork2.Preparable;@Namespace("/")@ParentPackage("default")public class FirstAction extends ActionSupport implements Preparable {    private static final long serialVersionUID = 1L;    private String test;    @Override    public void prepare() throws Exception {        System.out.println("这是所有方法前的处理");    }    @Action(value = "test",             results = { @Result(name = "success1", location = "/index2.jsp", type = "redirect") ,                        @Result(name = "error", location = "/index2.jsp") ,                        @Result(name = "success" ,type = "json" , params = {"root","test"})                         })    @Override    public String execute() throws Exception {        test = "test";        return super.execute();    }        public void prepareHaha() {        System.out.println("haha 执行前面");    }    @Action(value = "haha" ,results ={@Result(name = "success", location = "/index2.jsp", type = "redirect")} )    public String haha() throws Exception {        return super.execute();    }    public String getTest() {        return test;    }    public void setTest(String test) {        this.test = test;    }    }

 

结果:

　　haha 执行前面

　　这是所有方法前的处理