自定義類型轉換器要繼承StrutsTypeConverter抽象類,實現如下兩個方法
(1)public Object converFromString(Map context, String[] values. Class toClass)實現字符串向對象的轉換
- context:轉換上下文,可以在裏面引用各種對象
- values:用戶輸入的字符串
- toClass:將要被轉換成的對象類型
- context:轉換上下文
- o:需要被轉換的對象
<package name="main" extends="struts-default">
<action name="convert" class="com.java.struts2.action.ConverterAction">
<result name="success">/success.jsp</result>
</action>
</package>
ConvertActionpackage com.java.struts2.action;
import com.opensymphony.xwork2.ActionSupport;
public class ConverterAction extends ActionSupport {
private Rectangle rectangle;
public Rectangle getRectangle() {
return rectangle;
}
public void setRectangle(Rectangle rectangle) {
this.rectangle = rectangle;
}
public String execute() throws Exception {
return SUCCESS;
}
}
自定義轉換器RectangleConverterpackage com.java.struts2.action;
import java.util.Map;
import org.apache.struts2.util.StrutsTypeConverter;
import com.opensymphony.xwork2.conversion.TypeConversionException;
public class RectangleConverter extends StrutsTypeConverter {
public Object convertFromString(Map context, String[] values, Class toClass) {
//用戶輸入,比如16:25
String userInput = values[0];
String[] arr = userInput.split(":");
//在真正的格式轉換之前先把所有的用戶輸入可能的錯誤攔截
if(arr.length != 2) {
throw new TypeConversionException("請輸入正確的長方形格式如:width:height");
}
try {
Rectangle rectangle = new Rectangle();
int width = Integer.parseInt(arr[0]);
int height = Integer.parseInt(arr[1]);
rectangle.setWidth(width);
rectangle.setHeight(height);
return rectangle;
} catch (Exception e) {
throw new TypeConversionException("請輸入正確的長方形格式如:width:height", e);
}
}
public String convertToString(Map context, Object o) {
Rectangle rectangle = (Rectangle) o;
return "長方形:寬" + rectangle.getWidth() + ",高" + rectangle.getHeight();
}
}
註冊自定義類型轉換器(src下創建)com.java.struts2.action.Rectangle =com.java.struts2.action.RectangleConverter
表單:<s:form action="/convert.action" method="post">
<s:textfield name="rectangle" label="輸入長和寬" />
<s:submit value="提交" />
</s:form>
成功輸出頁面:<s:property value="rectangle"/>