Strts06 - Interceptor, File Processing

Keywords: Struts xml Session

struts Initial Knowledge 6-Interceptor

1. Interceptor use

1.1 Custom Interceptor

  • Method:

    1. Create common classes, inherit AbstractIntercepter, and implement abstract methods

    2.struts.xml configuration interceptor:

    2.1 Declare Interceptor

    2.2 Use interceptors:

    	> Note that all default interceptors do not work after configuring the interceptor
    	> Solutions:
    	> 1. Call the default stack Interceptor at every place where the interceptor is used
    	> Disadvantage: You need to call the default interceptor stack everywhere you use the interceptor
    	> 2. At your own interceptor, call the default stack interceptor group and add your own interceptor
    	> Advantages: You don't need to configure multiple interceptors in every place where interceptors are used, just configure your own interceptors.
    	> Disadvantage: You still need to use interceptors everywhere.
    	> 3. Configure intercepting XML to configure itself as the default interceptor
    	> Disadvantage: Intercept everything, and intercept anything that does not need to be intercepted.
    	> 4. Solution: There is an abstract class in the AbstractIninterceptor subclass - MethodFilterInterceptor:
    	> excludeMethod: No interception is required
    	> Include Method: Need to intercept
    	> Disadvantage: When declaring an interceptor, you don't know which methods need to be intercepted and which don't need to be intercepted.
    	> 5. Interception in Use

2. Processes

2.1 Execution process

  • Interception - > (If there is a next interceptor, let it go to the next interceptor) - > Last interceptor let it go - > Reaching the target resource

3. Practice

3.1 Login Control

  • Logon Interception Class

    public class LoginInterceptor extends MethodFilterInterceptor {
          * @Author ANGLE0
          * @Description Determine whether there are objects in the session domain
          * @Date 10:41 2019/7/28
          * @Param
          * @return
        protected String doIntercept(ActionInvocation actionInvocation) throws Exception {
            Object obj = ActionContext.getContext().getSession().get("loginStaff");
                //Not logged in, pointing to the logon page
            if (obj == null) {
                return "login";
                //Logged in
            return actionInvocation.invoke();
  • strtus.xml configuration interceptor

    There are two ways to configure interceptors:

    Method 1: Define your own interceptor directly, and then configure the interceptor in action

    Method 2: Pack default interceptors and custom interceptors into stacks and then configure them into action

    • Method 1
    //Custom Interceptor
    <interceptor name="loginInterceptor" class=""></interceptor>
    //Reference in action
    <action name="">
    	//Reference to the default stack
    	<interceptor-ref name="defaultStack"></interceptot-ref>
    	//Call your own interceptor	
    	<interceptor-ref name="loginInterceptor"></interceptot-ref>
    • Stack Packing
        <!--Custom stack-->
        <interceptor-stack name="loginInterceptorStack">
            <interceptor-ref name="default-stack"></interceptor-ref>
            <interceptor-ref name="loginInterceptor"></interceptor-ref>
    • Declare default
        <!--3.1 Declare interceptor, register interceptor-->
        <interceptor name="loginInterceptor" class=""></interceptor>
        <!--3.2 Declare the interceptor stack, action Quote-->
        <interceptor-stack name="loginStack">
            <interceptor-ref name="default-stack"></interceptor-ref>
            <!--Configure methods that do not require interception. exculeMethod Configure methods that do not require interception"Division"-->
            <interceptor-ref name="loginInterceptor">
                <param name="excludeMethods">login</param>
    <!--3.3 Declare default-->
    <default-interceptor-ref name="loginStack"></default-interceptor-ref>

3.2 File Upload

Properties of uploaded files provided by 3.2.1 Struts Library

  • photoFileName: Upload File Name
  • photoContentType: File type

3.2.2 File Cache

  • <10KB: Memory as Cache
  • > 10KB: Disk temporary file as cache

3.2.3 File Processing Mode copies

  • Copy it to the specified location (temporary file processing is still in progress) shear

  • Cut the temporary file to the specified location and rename it (the temporary file has been processed and is no longer there)

3.2.4 Modification Limits Upload File Size

  • Modifying Constants
  • Modifying File Restrictions by Injecting Parameters

3.2.5 Multi-file Upload

3.3 File Download

3.3.1 Small bug

  • The variable name of InputStream in the download action class cannot be used in
  • Determine whether the picture has been P, the text is open, and whether the first voyage has been E.... Subsample

Posted by squimmy on Thu, 05 Sep 2019 01:36:30 -0700