STRUTS2 custom type conversions, and handling type conversion errors

Struts2 Custom type conversions:

The types received from the foreground are all strings, and some of the basic type conversions from theStruts2 sometimes do not meet our special needs, such as: date string input format, and some custom classes, directly to the background, we need some of our own converters:

Example :

I have a point type:

Package Cn.jnit.bean;

public class Point {

Private Integer x;

Private Integer y;

Public Point () {

}

Public point (Integer x, integer y) {

this.x = x;

This.y = y;

}

Public Integer GetX () {

return x;

}

public void SetX (Integer x) {

this.x = x;

}

Public Integer GetY () {

return y;

}

public void Sety (Integer y) {

This.y = y;

}

}

Test type converter: My front-desk struts form

<s:form action= "point" method= "POST" >

<s:textfield name= "Point" ></s:textfield>

<s:submit value= "Submit" ></s:submit>

</s:form>

<%--<s:property value= "point"/>--%>

Action for the form:

Package cn.jnit.action;

Import Cn.jnit.bean.Point;

Import Com.opensymphony.xwork2.ActionSupport;

public class Convertacion extends actionsupport{

private point Point;

@Override

Public String Execute () throws Exception {

System.out.println (Point.getx ());

System.out.println (Point.gety ());

return SUCCESS;

}

Public Point GetPoint () {

return point;

}

public void SetPoint (point point) {

This.point = point;

}

}

We found the Xwork-core-2.2.1.jar core pack.COM.OPENSYMPHONY.XWORK2in thecom.opensymphony.xwork2.conversionin theTypeconverter.classin theCom.opensymphony.xwork2.conversion.TypeConverterInterfaces: ImplementingTypeConverterthe interface class hasDefaulttypeconverterclass, we can see the inheritance fromDefaulttypeconverterClass has an abstract class in the classStrutstypeconverter, our custom classes inherit from theStrutstypeconverter, and then rewrite the two methods:

1: encapsulating string Data from the foreground into objects

@Override

Public Object convertfromstring (Map context, string[] values, Class toclass) {}

2: convert background object back to string data echo to foreground

@Override

Public String converttostring (Map context, Object o) {}

Then my custom conversion class:

Package Cn.jnit.convert;

Import Java.util.Arrays;

Import Java.util.Map;

Import Org.apache.struts2.util.StrutsTypeConverter;

Import com.opensymphony.xwork2.conversion.TypeConversionException;

Import Cn.jnit.bean.Point;

public class Myconvert extends Strutstypeconverter {

@Override

Public Object convertfromstring (Map context, string[] values, Class toclass) {

/* SYSTEM.OUT.PRINTLN ("--------------------------Map---------------");

For (Object Obj:context.keySet ()) {

System.out.println (obj);

}

System.out.println ("-------------------------------");

System.out.println (arrays.tostring (values));

System.out.println ("-----------class--------------------");

System.out.println (Toclass);

System.out.println ("-------------------------------------------"); */

Point P=new Point ();

System.out.println (Values[0]);

String string =values[0].split (",") [0];

if (! ( Values[0].length () >0&&values[0].matches ("\\d{2,5},\\d{2,5}")) {

throws an exception if the value entered in the foreground page does not match the value of the split in my custom type conversion method

throw new Typeconversionexception ();

}

P.setx (Integer.valueof (Values[0].split (",") [0]);

P.sety (Integer.valueof (Values[0].split (",") [1]);

TODO auto-generated Method Stub

return p;

}

@Override

Public String converttostring (Map context, Object o) {

Point p= o;

return P.getx () + "," +p.gety ();

}

}

Because of the form that Struts comes with, the error message is automatically added to the submitted label, and if you use an HTML form, you need to add <s:fielderror> </s:fielderror> will display an error message ( a form that isrecommended with struts).

However, the error message is strut2 's own English message, if you want to change the error message, then we have two options:

The first is the type converter that is applied to the global scope, specifically:

First we need to add in struts.xml :

<constant name= "struts.custom.i18n.resources" value= "message" ></constant>

Because by default, all type conversion errors are generic i18n message keys

Xwork-default.invalid.fieldvalue to report the error message. Then we need to create a message.properties file under src , and then the inside is simply right:Name: Xwork.default.invalid.fieldvalue value: Invalid values for field '{0}' (in Properties view, if you use the Source The view is displayed as:xwork.default.invalid.fieldvalue=\u5b57\u6bb5\u201c{0}\u201d\u7684\u503c\u65e0\u6548

）

The second is to apply a type converter for a particular class, specifically:

In the action package, create a properties file with the same name as the action , and the Name=value are:

Invalid.fieldvalue.point=point conversion error,

If this class is a custom type, you need to add one: the -conversion.properties file with the same name as the Action name The value is point,value : The full class name of the custom type converter, such as:Point=cn.jnit.convert.myconvert

Finally remember that all properties file name a letter can not be wrong, otherwise no effect!

STRUTS2 custom type conversions, and handling type conversion errors