JSP 不使用 Spring Boot 和 MongoDB 进行渲染答案

【问题标题】：JSP not rendering using Spring Boot and MongoDBJSP 不使用 Spring Boot 和 MongoDB 进行渲染
【发布时间】：2019-01-30 21:25:31
【问题描述】：

我正在尝试在 Spring Boot 中运行 JSP，但显示的只是 welcome 这个词，而不是我的实际内容。在调用 MongoDB 之后调用 JSP。当我从我的 Java 代码调用 MongoDB 时，我也会遇到这些异常。

com.mongodb.MongoSocketReadTimeoutException: Timeout while receiving message at com.mongodb.internal.connection.InternalStreamConnection.translateReadException(InternalStreamConnection.java:553) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.receiveMessage(InternalStreamConnection.java:444) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.receiveCommandMessageResponse(InternalStreamConnection.java:295) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.sendAndReceive(InternalStreamConnection.java:255) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.CommandHelper.sendAndReceive(CommandHelper.java:83) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.CommandHelper.executeCommand(CommandHelper.java:33) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnectionInitializer.initializeConnectionDescription(InternalStreamConnectionInitializer.java:106) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnectionInitializer.initialize(InternalStreamConnectionInitializer.java:63) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:127) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117) ~[mongo-java-driver-3.9.1.jar:na] at java.base/java.lang.Thread.run(Thread.java:844) [na:na] Caused by: java.net.SocketTimeoutException: Read timed out at java.base/java.net.SocketInputStream.socketRead0(Native Method) ~[na:na] at java.base/java.net.SocketInputStream.socketRead(SocketInputStream.java:116) ~[na:na] at java.base/java.net.SocketInputStream.read(SocketInputStream.java:171) ~[na:na] at java.base/java.net.SocketInputStream.read(SocketInputStream.java:141) ~[na:na] at com.mongodb.internal.connection.SocketStream.read(SocketStream.java:109) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.receiveResponseBuffers(InternalStreamConnection.java:570) ~[mongo-java-driver-3.9.1.jar:na] at com.mongodb.internal.connection.InternalStreamConnection.receiveMessage(InternalStreamConnection.java:441) ~[mongo-java-driver-3.9.1.jar:na] ... 9 common frames omitted

welcome.jsp

<!DOCTYPE html>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html lang="en" ng-app="employeeApp">
<head>
    <title>Frank's App</title>
        <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
        <script src="app.js"></script>
        <style>
            table, th, td {
                border: 1px solid black;
            }
        </style>
    </head>
<body>
    <h2>Frank's App</h2>
    <div ng-app="myApp" ng-controller="myCtrl">
        <table>
            <tr>
                <th>First Name</th>
                <th>Last Name</th>
                <th>Employee Number</th>
                <th>Pay Rate</th>
            </tr>
            <tr ng-repeat="employee in employees">
                <td>{{ employee.firstName }}</td>
                <td>{{ employee.lastName }}</td>
                <td>{{ employee.empNumber }}</td>
                <td>{{ employee.payRate }}</td>
            </tr>
        </table>
    </div>
</body>

控制器代码：

@RequestMapping("/welcome")
public String welcome(Model model) {
    model.addAttribute("employees", getEmployees());
    return "welcome";
}

@RequestMapping("/getEmployees")
public List<Employee> getEmployees() {
    MongoDatabase db = getDatabase();
    MongoCollection<Document> collection = db.getCollection(COLLECTION);
    Document query = new Document();
    List<Employee> employees = collection.find(query, Employee.class).into(new ArrayList<Employee>());
    return employees;
}

private MongoDatabase getDatabase() {
    CodecRegistry pojoCodecRegistry =     org.bson.codecs.configuration.CodecRegistries.fromRegistries(
            MongoClientSettings.getDefaultCodecRegistry(),     org.bson.codecs.configuration.CodecRegistries.fromProviders(PojoCodecProvider.builder().automatic(true).build()));
    MongoDatabase database = mongo.getDatabase("testdb").withCodecRegistry(pojoCodecRegistry);
    return database;
}

【问题讨论】：

标签： spring mongodb spring-boot jsp

【解决方案1】：

您不会在 HTML 代码中使用 JSP，它是 Angular 框架。 Angular 不会读取您在控制器中作为“员工”属性推送的数据。

改为这个

<tr ng-repeat="employee in employees">
                <td>{{ employee.firstName }}</td>
                <td>{{ employee.lastName }}</td>
                <td>{{ employee.empNumber }}</td>
                <td>{{ employee.payRate }}</td>
</tr>

使用 JSP 语法，像这样

<c:forEach var="employee" items="${employees}">
            <tr>
                <td>${employee.firstName}</td>
                <td>${employee.lastName}</td>
                <td>${employee.empNumber}</td>
                <td>${employee.payRate}</td>
            </tr>
</c:forEach>