struts2学习之四、类型转换2

<h3><font color="red">使用x坐标，y坐标分两行</font></h3>
   
   <s:form action="pointConverter">
   
   <s:textfield name="point.x" label="x"></s:textfield>
   <s:textfield name="point.y" label="y"></s:textfield>
   <s:textfield name="age" label="age"></s:textfield>
   <s:textfield name="username" label="username"></s:textfield>
   <s:textfield name="date" label="birthday"></s:textfield>
   
   <s:submit label="submit"></s:submit>
   
   </s:form>

 一、当输入页面有多个Point类的对象时，point，point2，point3
那么相应的输入页面，结果页面，PointAction，PointAction-conversion.properties都改成三个。
point=com.test.converter.PointConverter
point2=com.test.converter.PointConverter
point3=com.test.converter.PointConverter

 

二、那么如果有十个呢？不是需要在配置文件中写十个，比较麻烦
有以下方法：全局的类型的类型转换
位置Src目录下，不在和相应的Action在一起了
名字叫xwork-conversion.properties
内容：com.test.bean.Point=com.test.converter.PointConverter
等号左边表示的需要转化的类名（含包名），右侧是转化类。

 

三、此时举例的转换类PointConverter2.java（基于Struts2的）更加简洁。一般正式项目中用的也是这个。
//继承StrutsTypeConverter并且重写convertFromString（）和convertToString方法。

package com.test.converter;
import java.util.Map;
import org.apache.struts2.util.StrutsTypeConverter;
import com.test.bean.Point;
public class PointConverter2 extends StrutsTypeConverter
{

 @Override
 public Object convertFromString(Map context, String[] values, Class toClass)
 {
  Point point = new Point();
  
  String[] paramValues = values[0].split(",");
  
  int x = Integer.parseInt(paramValues[0]);
  int y = Integer.parseInt(paramValues[1]);
  
  point.setX(x);
  point.setY(y);
  
  return point;
 }

 @Override
 public String convertToString(Map context, Object o)
 {
  Point point = (Point)o;
  
  int x = point.getX();
  int y = point.getY();
  
  String result = "[ x = " + x + " , y = " + y + " ]";
  
  return result;
 }

}

 

四、转换集合类型 List<Point>
1）即在PointAction.java类为

package com.test.action;

import java.util.Date;
import java.util.List;

import com.opensymphony.xwork2.ActionSupport;
import com.test.bean.Point;

public class PointAction extends ActionSupport
{

private List<Point> point; 
 private int age;
 private String username;
 private Date date;
 public List<Point> getPoint()
 {
  return point;
 }

 public void setPoint(List<Point> point)
 {
  this.point = point;
 }
 
 public int getAge()
 {
  return age;
 }

 public void setAge(int age)
 {
  this.age = age;
 }

 public String getUsername()
 {
  return username;
 }

 public void setUsername(String username)
 {
  this.username = username;
 }

 public Date getDate()
 {
  return date;
 }

 public void setDate(Date date)
 {
  this.date = date;
 }

 @Override
 public String execute() throws Exception
 {
  return SUCCESS;
 }

}

 

 

2）此时的转化类可修改为PointConverter3.java

package com.test.converter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.struts2.util.StrutsTypeConverter;
import com.test.bean.Point;

public class PointConverter3 extends StrutsTypeConverter
{

 @Override
 public Object convertFromString(Map context, String[] values, Class toClass)
 {
  List<Point> list = new ArrayList<Point>();
  
  for(String value : values)
  {
   Point point = new Point();
   
   String[] paramValues = value.split(",");
   
   int x = Integer.parseInt(paramValues[0]);
   int y = Integer.parseInt(paramValues[1]);
   
   point.setX(x);
   point.setY(y);
   
   list.add(point);
  }
  
  return list;
 }

 @Override
 public String convertToString(Map context, Object o)
 {
  List<Point> list = (List<Point>)o;
  
  StringBuilder sb = new StringBuilder();
  
  sb.append("[ ");
  
  int number = 0 ;
  
  for(Point point : list)
  {
   ++number;
   
   int x = point.getX();
   int y = point.getY();
   
   sb.append(number).append(" x = ").append(x).append(" , y = ").append(y).append("  ");
  }
  
  sb.append("]");
  
  return sb.toString();
 }

}

 

3)input.jsp

<s:form action="pointConverter">
   
   <s:textfield name="point" label="point"></s:textfield>
   <s:textfield name="point" label="point2"></s:textfield>
   <s:textfield name="point" label="point3"></s:textfield>
   <s:textfield name="age" label="age"></s:textfield>
   <s:textfield name="username" label="username"></s:textfield>
   <s:textfield name="date" label="birthday"></s:textfield>   
   <s:submit label="submit"></s:submit> 
   </s:form>

 

4)output.jsp

 point:<s:property value="point"/><br>
 age:<s:property value="age"/><br>
 username:<s:property value="username"/><br>
 date:<s:property value="date"/><br>

  

五、将x坐标，y坐标分两行输入页面
1)input.jsp

2）此时就不用任何类型转化了，就可以自动准确输出了

3）采用这种方式“.”对象.属性的方式的话，Point必须提供一个不带参数的构造方法
其实strut2内部采用了反射的机制！不建意用这个方式，表单太罗嗦了。