ajax 调用 jersey rest web 服务中的 Access-Control-Allow-Origin

2022-01-15 00:00:00 json cors rest ajax java

我使用 jersey JAX-Rs 作为 Web 服务来查询 mysql.我尝试通过混合移动应用程序使用 Web 服务.

I used jersey JAX-Rs as web service to query mysql.I try to consume the web-service via hybrid mobile application .

我参考这个http://coenraets.org/blog/2011/11/building-restful-services-with-java-using-jax-rs-and-jersey-sample-application/#comment-440541

在服务器端运行以下代码在tomcat server7中查询sql

In server side the following code running in tomcat server7 to query sql

@Path("/employees")
 public class EmployeeResource {

EmployeeDAO dao = new EmployeeDAO();

@GET
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public List<Employee> findAll() {
    return dao.findAll();
}
}

公共类 EmployeeDAO {

public class EmployeeDAO {

public List<Employee> findAll() {
    List<Employee> list = new ArrayList<Employee>();
    Connection c = null;
String sql = "SELECT e.id, e.firstName, e.lastName, e.title FROM employee as e";

    try {
        c = ConnectionHelper.getConnection();
        Statement s = c.createStatement();
        ResultSet rs = s.executeQuery(sql);
        while (rs.next()) {
            list.add(processSummaryRow(rs));
        }
    } catch (SQLException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
    } finally {
        ConnectionHelper.close(c);
    }
    return list;
}

protected Employee processSummaryRow(ResultSet rs) throws SQLException {
        Employee employee = new Employee();
        employee.setId(rs.getInt("id"));
        employee.setFirstName(rs.getString("firstName"));
        employee.setLastName(rs.getString("lastName"));
        employee.setTitle(rs.getString("title"));
        /*employee.setPicture(rs.getString("picture"));
        employee.setReportCount(rs.getInt("reportCount"));*/
        return employee;
    }

}

我已经创建了数据库目录，表名作为员工，字段 id,firstName,lastName,title.

I have been created the database directory with table name as employee with fields id,firstName,lastName,title.

现在我在 same project 的 web-content 文件夹中有 html 文件.

Now i have the html file in the web-content folder of the same project .

<!DOCTYPE HTML>
<html>
    <head>
        <title>Employee Directory</title>
    </head>

    <body>

    <h1>Employee Directory</h1>

    <ul id="employeeList"></ul>

    <script src="http://code.jquery.com/jquery-1.7.min.js"></script>
    <script src="js/employeelist.js"></script>

    </body>

</html>

员工名单

getEmployeeList();
        function getEmployeeList() {
            $.getJSON(serviceURL + 'employees', function(data) {
                $('#employeeList li').remove();
                var employees = data.employee;
                $.each(employees, function(index, employee) {
                    $('#employeeList').append(
                        '<li><a href="employeedetails.html#' + employee.id + '">'
                        + employee.firstName + ' ' + employee.lastName + ' (' 
                        + employee.title + ')</a></li>');
                });
            });
        }

这将在索引页面中显示准确的员工详细信息.

This will shows the extact employee details in the Index page.

现在我已经在 another project 中创建了一个 html 页面，我将在其中放置与上面指定的相同的 $.getJSON 调用将在控制台中引发错误

Now i have been create an html page in another project where i will put same $.getJSON call which specified above will throw error in console as 

   XMLHttpRequest cannot load http://localhost:8181/jQueryJAXRS/rest/employees. Origin null is not allowed by Access-Control-Allow-Origin.

实际上我尝试使用客户端和服务器基础架构开发应用程序.所以我需要在客户端中有 html 文件才能在服务器端使用球衣网络服务.如果我制作 $.getJSON 或 $.ajax 真的很有帮助从另一个项目中的 html 文件调用以使用 Web 服务.

Actually I try to develop an application with client and server infrastructure .So i need to have html files in the client to consume the jersey web-services in serverside.It is really helpful if i make $.getJSON or $.ajax call from the html file in another project inorder to consume the web service.

when i use this url http://localhost:8181/jQueryJAXRS/rest/employees  in my browser

显示xml

<employees>
<employee>
<firstName>john</firstName>
<id>1</id>
<lastName>doe</lastName>
<reportCount>0</reportCount>
<title>trainee</title>
</employee>
<employee>
<firstName>james</firstName>
<id>2</id>
<lastName>dane</lastName>
<reportCount>0</reportCount>
<title>developer</title>
</employee>
<employee>
<firstName>ramsy</firstName>
<id>4</id>
<lastName>stuart</lastName>
<reportCount>0</reportCount>
<title>QA</title>
</employee>
</employees>

但是当我尝试通过脚本方式时，它会显示发生 CORS 错误.提出一些想法对我很有帮助.

but when i try through script way it will show CORS error occurs. Suggest some ideas will really help me.

提前致谢.

推荐答案

你必须使用 CORS.

为此:

  1. 你必须使用 cors-过滤罐

  2. 那么你必须在你的 web.xml 中使用一个过滤器:

  1. You have to use cors-filter jar

  2. Then you have to use a filter in your web.xml : 

<filter>
<filter-name>CORS</filter-name>
<filter-class>com.thetransactioncompany.cors.CORSFilter</filter-class>
<init-param>
    <param-name>cors.allowGenericHttpRequests</param-name>
    <param-value>true</param-value>
</init-param>
<init-param>
    <param-name>cors.allowOrigin</param-name>
    <param-value>*</param-value>
</init-param>
<init-param>
    <param-name>cors.allowSubdomains</param-name>
    <param-value>true</param-value>
</init-param>
<init-param>
    <param-name>cors.supportedMethods</param-name>
    <param-value>GET, HEAD, POST, OPTIONS</param-value>
</init-param>
<init-param>
    <param-name>cors.supportedHeaders</param-name>
    <param-value>Content-Type, X-Requested-With</param-value>
</init-param>
<init-param>
    <param-name>cors.exposedHeaders</param-name>
    <param-value>X-Test-1, X-Test-2</param-value>
</init-param>
<init-param>
    <param-name>cors.supportsCredentials</param-name>
    <param-value>true</param-value>
</init-param>
<init-param>
    <param-name>cors.maxAge</param-name>
    <param-value>-1</param-value>
</init-param>
</filter>


<filter-mapping>
<filter-name>CORS</filter-name>
 <url-pattern>/EmployeeResource</url-pattern>
</filter-mapping>

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