Jakarta ee 如何从WEB-INF加载图像？

只要图像在

web

中，这就可以正常工作；当图像位于

WEB-INF

中时，如何加载图像

NetBeansProjects/WebApplication/
├── build.xml
├── nbproject
│   ├── ant-deploy.xml
│   ├── build-impl.xml
│   ├── genfiles.properties
│   ├── private
│   ├── project.properties
│   └── project.xml
├── README.md
├── src
│   ├── conf
│   └── java
└── web
    ├── duke.gif
    ├── index.html
    └── WEB-INF

7 directories, 9 files

html:

登录
我叫苏菲尔，bjfdkl34363fjsl，你叫什么？
登录：

jsp:

登录
我的名字是${requestScope.controller.myName}，${requestScope.controller.myId}，你的名字是什么？
登录：


${sessionScope.authorization.greeting}

过滤器：

package net.bounceme.dur.webapp.filter;

import net.bounceme.dur.webapp.tokens.AuthenticationToken;
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@WebFilter(
        filterName = "authenticationFilter",
        description = "authentication",
        urlPatterns = "/*",
        initParams = {
            @WebInitParam(name = "1", value = "bart"),
            @WebInitParam(name = "2", value = "homer")})

public class AuthenticationFilter implements Filter {

    private static final Logger log = Logger.getLogger(AuthenticationFilter.class.getName());
    private FilterConfig filterConfig = null;
    private final Map<String, String> mapOfUsers = new HashMap<>();
    private final AuthenticationToken token = new AuthenticationToken();
    private final String className = AuthenticationFilter.class.getName();
    private Map<String, String> parameters = new HashMap<>();
    private Map<String, String> users = new HashMap<>();
    private boolean auth = false;
    private String contextPath;

    public AuthenticationFilter() {
    }

    private void doBeforeProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        log.fine("do before processing..");  //init?
    }

    private void doAfterProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        log.fine("do after processing");  //add image here?
    }

    private void initFilterParams() {
        log.info(className + "\tinitFilterParams..");
        Enumeration parameterNames = filterConfig.getInitParameterNames();
        users = new HashMap<>();  //?
        String name = null;
        String val = null;
        while (parameterNames.hasMoreElements()) {
            name = parameterNames.nextElement().toString();
            val = filterConfig.getInitParameter(name);
            users.put(name, val);
        }
        log.info(className + "\n" + users);
        log.info(className + "\t..initFilterParams");
    }

    private void initParams(HttpServletRequest request) {
        log.info(className + "\tinitParams..");
        parameters = new HashMap<>();  //?
        Enumeration<String> params = request.getParameterNames();
        String name = null;
        String val = null;
        while (params.hasMoreElements()) {
            name = params.nextElement();
            val = request.getParameter(name);
            parameters.put(name, val);
        }
        log.info(className + "\n" + parameters);
        log.info(className + "\t..initParams");
    }

    private void setToken(HttpServletRequest request) {
        initParams(request);
        String login = null;
        if (parameters.containsKey("login")) {
            login = parameters.get("login").toLowerCase();
            token.setLogin(login);
            if (users.containsValue(login)) {
                auth = true;
                token.setGreeting("welcome " + login + " you've been authorized.");
            } else {
                auth = false;
                token.setGreeting("welcome " + login);
            }
        } else {
            auth = false;
        }
        HttpSession session = request.getSession(false);
        if (session != null) {
            session.setAttribute("authorization", token);
        }
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info(className + "do filter..");
        setToken((HttpServletRequest) request);
        chain.doFilter(request, response);
        log.info(className + "..do filter");
    }

    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
    }

    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }

    @Override
    public void destroy() {
    }

    @Override
    public void init(FilterConfig filterConfig) {
        log.info(className + "\tinit..");
        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            log.fine("SessionCheckFilter:Initializing filter");
        } else {
            log.warning("null filterConfig");
        }
        String context = filterConfig.getServletContext().getServletContextName();
        String path = filterConfig.getServletContext().getContextPath();
        contextPath = "http://localhost:8080" + context + path;
        String duke = contextPath + "/duke.gif";
        token.setDuke(duke);
        initFilterParams();
        log.info(token.toString());
        log.info(className + "\t..init");
    }

    @Override
    public String toString() {
        return token.toString();
    }

    private void sendProcessingError(Throwable t, ServletResponse response) {
        log.fine("send processing error");
        String stackTrace = getStackTrace(t);

        if (stackTrace != null && !stackTrace.equals("")) {
            try {
                response.setContentType("text/html");
                try (PrintStream ps = new PrintStream(response.getOutputStream()); PrintWriter pw = new PrintWriter(ps)) {
                    pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N
                    pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                    pw.print(stackTrace);
                    pw.print("</pre></body>\n</html>"); //NOI18N
                }
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        } else {
            try {
                try (PrintStream ps = new PrintStream(response.getOutputStream())) {
                    t.printStackTrace(ps);
                }
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        }
    }

    public static String getStackTrace(Throwable t) {
        String stackTrace = null;
        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch (Exception ex) {
        }
        log.warning(stackTrace);
        return stackTrace;
    }

}

package net.bounceme.dur.webapp.filter；
导入net.bounceme.dur.webapp.tokens.AuthenticationToken；
导入java.io.IOException；
导入java.io.PrintStream；
导入java.io.PrintWriter；
导入java.io.StringWriter；
导入java.util.Enumeration；
导入java.util.HashMap；
导入java.util.Map；
导入java.util.logging.Logger；
导入javax.servlet.Filter；
导入javax.servlet.FilterChain；
导入javax.servlet.FilterConfig；
导入javax.servlet.ServletException；
导入javax.servlet.ServletRequest；
导入javax.servlet.ServletResponse；
导入javax.servlet.annotation.WebFilter；
导入javax.servlet.annotation.WebInitParam；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpSession；
@网络过滤器(
filterName=“authenticationFilter”，
description=“身份验证”，
urlPatterns=“/*”，
initParams={
@WebInitParam（name=“1”，value=“bart”），
@WebInitParam（name=“2”，value=“homer”）}）
公共类AuthenticationFilter实现筛选器{
私有静态最终记录器log=Logger.getLogger（AuthenticationFilter.class.getName（））；
private FilterConfig FilterConfig=null；
private final Map mapOfUsers=新HashMap（）；
private final AuthenticationToken token=新的AuthenticationToken（）；
私有最终字符串className=AuthenticationFilter.class.getName（）；
私有映射参数=new HashMap（）；
私有映射用户=新HashMap（）；
私有布尔auth=false；
私有字符串上下文路径；
公共身份验证筛选器（）{
}
私有void doBeforeProcessing（ServletRequest请求、ServletResponse响应）抛出IOException、ServletException{
log.fine（“处理前执行…”；//初始化？
}
私有void doAfterProcessing（ServletRequest请求、ServletResponse响应）引发IOException、ServletException{
log.fine（“处理后执行”）；//是否在此处添加图像？
}
私有void initFilterParams（）{
log.info（className+“\tinitFilterParams..”；
枚举parameterNames=filterConfig.getInitParameterNames（）；
users=新HashMap（）；/？
字符串名称=null；
字符串val=null；
while（parameterNames.hasMoreElements（））{
name=parameterNames.nextElement（）.toString（）；
val=filterConfig.getInitParameter（名称）；
users.put（名称，val）；
}
log.info（className+“\n”+用户）；
log.info（className+“\t..initFilterParams”）；
}
私有void initParams（HttpServletRequest请求）{
log.info（className+“\t图片..”）；
参数=新HashMap（）；/？
枚举参数=request.getParameterNames（）；
字符串名称=null；
字符串val=null；
while（params.hasMoreElements（））{
name=params.nextElement（）；
val=request.getParameter（名称）；
参数.put（名称，val）；
}
log.info（className+“\n”+参数）；
log.info（className+“\t..initParams”）；
}
私有void setToken（HttpServletRequest请求）{
initParams（请求）；
字符串login=null；
if（parameters.containsKey（“登录”））{
login=parameters.get（“login”）.toLowerCase（）；
token.setLogin（login）；
if（users.containsValue（登录））{
auth=true；
setGreeting（“欢迎”+登录+“您已被授权”）；
}否则{
auth=false；
token.setGreeting（“欢迎”+登录）；
}
}否则{
auth=false；
}
HttpSession session=request.getSession（false）；
if（会话！=null）{
session.setAttribute（“授权”，令牌）；
}
}
@凌驾
public void doFilter（ServletRequest请求、ServletResponse响应、FilterChain链）抛出IOException、ServletException{
log.info（className+“do filter..”）；
setToken（（HttpServletRequest）请求）；
链式过滤器（请求、响应）；
log.info（className+“.do过滤器”）；
}
公共筛选器配置getFilterConfig（）{
返回（this.filterConfig）；
}
public void setFilterConfig（FilterConfig FilterConfig）{
this.filterConfig=filterConfig；
}
@凌驾
公共空间销毁（）{
}
@凌驾
public void init（FilterConfig FilterConfig）{
log.info（className+“\tinit..”；
this.filterConfig=filterConfig；
if（filterConfig！=null）{
log.fine（“SessionCheckFilter:initializefilter”）；
}否则{
日志警告（“空过滤器配置”）；
}
字符串上下文=filterConfig.getServletContext（）.getServletContextName（）；
字符串路径=filterConfig.getServletContext（）.getContextPath（）；
上下文路径=”http://localhost:8080“+上下文+路径；
字符串duke=contextPath+“/duke.gif”；
代币。塞杜克（杜克）；
initFilterParams（）；
log.info（token.toString（））；
log.info（className+“\t..init”）；
}
@凌驾
公共字符串toString（）{
返回token.toString（）；
}
private void sendProcessingError（Throwable t，ServletResponse响应）{
对数鳍
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>login</title>
    </head>
    <body>
        <img src="${sessionScope.authorization.duke}"> 
        my name is ${requestScope.controller.myName}, ${requestScope.controller.myId}, what's yours?
        <form name="user_name_form" action="controller" method="POST">
            login: <input type="text" name="login" value="" size='20' />
            <p>
                <input type="submit">
            </p>
        </form>
        ${sessionScope.authorization.greeting}
    </body>
</html>

package net.bounceme.dur.webapp.filter;

import net.bounceme.dur.webapp.tokens.AuthenticationToken;
import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

@WebFilter(
        filterName = "authenticationFilter",
        description = "authentication",
        urlPatterns = "/*",
        initParams = {
            @WebInitParam(name = "1", value = "bart"),
            @WebInitParam(name = "2", value = "homer")})

public class AuthenticationFilter implements Filter {

    private static final Logger log = Logger.getLogger(AuthenticationFilter.class.getName());
    private FilterConfig filterConfig = null;
    private final Map<String, String> mapOfUsers = new HashMap<>();
    private final AuthenticationToken token = new AuthenticationToken();
    private final String className = AuthenticationFilter.class.getName();
    private Map<String, String> parameters = new HashMap<>();
    private Map<String, String> users = new HashMap<>();
    private boolean auth = false;
    private String contextPath;

    public AuthenticationFilter() {
    }

    private void doBeforeProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        log.fine("do before processing..");  //init?
    }

    private void doAfterProcessing(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        log.fine("do after processing");  //add image here?
    }

    private void initFilterParams() {
        log.info(className + "\tinitFilterParams..");
        Enumeration parameterNames = filterConfig.getInitParameterNames();
        users = new HashMap<>();  //?
        String name = null;
        String val = null;
        while (parameterNames.hasMoreElements()) {
            name = parameterNames.nextElement().toString();
            val = filterConfig.getInitParameter(name);
            users.put(name, val);
        }
        log.info(className + "\n" + users);
        log.info(className + "\t..initFilterParams");
    }

    private void initParams(HttpServletRequest request) {
        log.info(className + "\tinitParams..");
        parameters = new HashMap<>();  //?
        Enumeration<String> params = request.getParameterNames();
        String name = null;
        String val = null;
        while (params.hasMoreElements()) {
            name = params.nextElement();
            val = request.getParameter(name);
            parameters.put(name, val);
        }
        log.info(className + "\n" + parameters);
        log.info(className + "\t..initParams");
    }

    private void setToken(HttpServletRequest request) {
        initParams(request);
        String login = null;
        if (parameters.containsKey("login")) {
            login = parameters.get("login").toLowerCase();
            token.setLogin(login);
            if (users.containsValue(login)) {
                auth = true;
                token.setGreeting("welcome " + login + " you've been authorized.");
            } else {
                auth = false;
                token.setGreeting("welcome " + login);
            }
        } else {
            auth = false;
        }
        HttpSession session = request.getSession(false);
        if (session != null) {
            session.setAttribute("authorization", token);
        }
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info(className + "do filter..");
        setToken((HttpServletRequest) request);
        chain.doFilter(request, response);
        log.info(className + "..do filter");
    }

    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
    }

    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }

    @Override
    public void destroy() {
    }

    @Override
    public void init(FilterConfig filterConfig) {
        log.info(className + "\tinit..");
        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            log.fine("SessionCheckFilter:Initializing filter");
        } else {
            log.warning("null filterConfig");
        }
        String context = filterConfig.getServletContext().getServletContextName();
        String path = filterConfig.getServletContext().getContextPath();
        contextPath = "http://localhost:8080" + context + path;
        String duke = contextPath + "/duke.gif";
        token.setDuke(duke);
        initFilterParams();
        log.info(token.toString());
        log.info(className + "\t..init");
    }

    @Override
    public String toString() {
        return token.toString();
    }

    private void sendProcessingError(Throwable t, ServletResponse response) {
        log.fine("send processing error");
        String stackTrace = getStackTrace(t);

        if (stackTrace != null && !stackTrace.equals("")) {
            try {
                response.setContentType("text/html");
                try (PrintStream ps = new PrintStream(response.getOutputStream()); PrintWriter pw = new PrintWriter(ps)) {
                    pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N
                    pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                    pw.print(stackTrace);
                    pw.print("</pre></body>\n</html>"); //NOI18N
                }
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        } else {
            try {
                try (PrintStream ps = new PrintStream(response.getOutputStream())) {
                    t.printStackTrace(ps);
                }
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        }
    }

    public static String getStackTrace(Throwable t) {
        String stackTrace = null;
        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch (Exception ex) {
        }
        log.warning(stackTrace);
        return stackTrace;
    }

}