1 Star 0 Fork 1

zhahl2025/HTTP-Proxy-Servlet

加入 Gitee
与超过 1200万 开发者一起发现、参与优秀开源项目,私有仓库也完全免费 :)
免费加入
克隆/下载
贡献代码
同步代码
取消
提示: 由于 Git 不支持空文件夾,创建文件夹后会生成空的 .keep 文件
Loading...
README
Apache-2.0

Smiley's HTTP Proxy Servlet

This is an HTTP Proxy (aka gateway) in the form of a Java servlet. An HTTP proxy is useful for AJAX applications to communicate with web accessible services on hosts other than where the web application is hosted. It's a reverse proxy, and not really a forwarding proxy albeit the template form of the servlet may blur that line.

This is hardly the first proxy, so why did I write it and thus why might you use it?

  • It's simple -- a single source file implementation
  • It's tested -- have confidence it works Build Status
  • It's securable -- via Java EE web.xml or via a servlet filter such as Spring-Security
  • It's extendible -- via simple class extension
  • It's embeddable -- into your Java web application making testing your app easier

I have seen many quick'n'dirty proxies posted in source form on the web such as in a blog. I've found such proxies to support a limited HTTP subset, such as only a GET request, or to suffer other implementation problems such as performance issues or URL escaping bugs. Disappointed at the situation, I set out to create a simple one that works well and that is well tested so I know it works. I suggest you use a well tested proxy instead of something non-tested that is perhaps better described as a proof-of-concept.

If you need something more sophisticated than there are some alternatives listed at the bottom of this page.

This proxy depends on Apache HttpClient, which offers another point of extension for this proxy. At some point I may write an alternative that uses the JDK and thus doesn't have any dependencies, which is desirable. In the meantime, you'll have to add the jar files for this and its dependencies:

 +- org.apache.httpcomponents:httpclient:jar:4.5.13:compile
    +- org.apache.httpcomponents:httpcore:jar:4.4.13:compile
    |  +- commons-logging:commons-logging:jar:1.2:compile
    |  \- commons-codec:commons-codec:jar:1.11:compile

This proxy supports HttpClient 4.3, and newer version too. If you need to support older HttpClient versions, namely 4.1 and 4.2, then use the 1.8 version of this proxy.

As of version 1.5 of the proxy, there is the ability to parameterize your proxy URL, allowing you to use the same web.xml servlet specification for multiple target servers. It follows the URI Template RFC, Level 1. Special query parameters (see the examples below) sent from the client to the ProxyServlet will map to the matching URL template, replacing arguments in the proxy's targetUri as specified in the web.xml. To use this, you must use a subclass of the base servlet. IMPORTANT! The template substitutions must be placed in the query string, even when using HTTP POST. Other application parameters can be in your POSTed url-encoded-form string; just not proxyArgs.

See CHANGES.md for a history of changes.

Build & Installation

Simply build the jar using "mvn package" at the command line. The jar is built to "target/smiley-http-proxy-servlet-VERSION.jar". You don't have to build the jar if you aren't modifying the code, since released versions are deployed to maven-central. If you are using maven then you can add this to your dependencies in your pom like so: (Note: the version below is not necessarily the latest.)

<dependency>
    <groupId>org.mitre.dsmiley.httpproxy</groupId>
    <artifactId>smiley-http-proxy-servlet</artifactId>
    <version>1.12</version>
</dependency>

Ivy and other dependency managers can be used as well.

Configuration

Parameters

The following is a list of parameters that can be configured

  • log: A boolean parameter name to enable logging of input and target URLs to the servlet log.
  • forwardip: A boolean parameter name to enable forwarding of the client IP
  • preserveHost: A boolean parameter name to keep HOST parameter as-is
  • preserveCookies: A boolean parameter name to keep COOKIES as-is
  • http.protocol.handle-redirects: A boolean parameter name to have auto-handle redirects
  • http.socket.timeout: A integer parameter name to set the socket connection timeout (millis)
  • http.read.timeout: A integer parameter name to set the socket read timeout (millis)
  • http.connectionrequest.timeout: A integer parameter name to set the connection request timeout (millis)
  • http.maxConnections: A integer parameter name to set max connection number
  • useSystemProperties: A boolean parameter whether to use JVM-defined system properties to configure various networking aspects.
  • targetUri: The parameter name for the target (destination) URI to proxy to.

Servlet

Here's an example excerpt of a web.xml file to communicate to a Solr server:

<servlet>
  <servlet-name>solr</servlet-name>
  <servlet-class>org.mitre.dsmiley.httpproxy.ProxyServlet</servlet-class>
  <init-param>
    <param-name>targetUri</param-name>
    <param-value>http://solrserver:8983/solr</param-value>
  </init-param>
  <init-param>
    <param-name>log</param-name>
    <param-value>true</param-value>
  </init-param>
</servlet>
<servlet-mapping>
  <servlet-name>solr</servlet-name>
  <url-pattern>/solr/*</url-pattern>
</servlet-mapping>

Here's an example with a parameterized proxy URL matching query parameters _subHost, _port, and _path such as "http://mywebapp/cluster/subpath?_subHost=namenode&_port=8080&_path=monitor". Note the different proxy servlet class. The leading underscore is not mandatory but it's good to differentiate them from the normal query parameters in case of a conflict.:

<servlet>
  <servlet-name>clusterProxy</servlet-name>
  <servlet-class>org.mitre.dsmiley.httpproxy.URITemplateProxyServlet</servlet-class>
  <init-param>
    <param-name>targetUri</param-name>
    <param-value>http://{_subHost}.behindfirewall.mycompany.com:{_port}/{_path}</param-value>
  </init-param>
  <init-param>
    <param-name>log</param-name>
    <param-value>true</param-value>
  </init-param>
</servlet>

<servlet-mapping>
  <servlet-name>clusterProxy</servlet-name>
  <url-pattern>/mywebapp/cluster/*</url-pattern>
</servlet-mapping>

SpringMVC

If you are using SpringMVC, then an alternative is to use its ServletWrappingController so that you can configure this servlet via Spring, which is supremely flexible, instead of having to modify your web.xml. However, note that some customization may be needed to divide the URL at the proxied portion; see Issue #15.

Spring Boot

If you are using Spring Boot, then consider this basic configuration:

@Configuration
public class SolrProxyServletConfiguration implements EnvironmentAware {

  @Bean
  public ServletRegistrationBean servletRegistrationBean() {
    ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new ProxyServlet(), propertyResolver.getProperty("servlet_url"));
    servletRegistrationBean.addInitParameter(ProxyServlet.P_TARGET_URI, propertyResolver.getProperty("target_url"));
    servletRegistrationBean.addInitParameter(ProxyServlet.P_LOG, propertyResolver.getProperty("logging_enabled", "false"));
    return servletRegistrationBean;
  }

  private RelaxedPropertyResolver propertyResolver;

  @Override
  public void setEnvironment(Environment environment) {
    this.propertyResolver = new RelaxedPropertyResolver(environment, "proxy.solr.");
  }
}

and properties in application.yml:

proxy:
    solr:
        servlet_url: /solr/*
        target_url: http://solrserver:8983/solr

It may be the case that Spring Boot (or Spring MVC) is consuming the servlet input stream before the servlet gets it, which is a problem.
See Issue #83 RE disabling FilterRegistrationBean.

Dropwizard

Addition of Smiley's proxy to Dropwizard is very straightforward.

Add a new property in the Dropwizard app .yml file

targetUri: http://foo.com/api  

Create a new configuration property

    @NotEmpty
    private String targetUri = "";

    @JsonProperty("targetUri")
    public String getTargetUri() {
        return targetUri;
    }  

Then register Smiley's proxy servlet with Jetty through the Dropwizard service's App run() method.

@Override
    public void run(final ShepherdServiceConfiguration configuration,
        final Environment environment) {

        environment.getApplicationContext()
            .addServlet("org.mitre.dsmiley.httpproxy.ProxyServlet", "foo/*")
            .setInitParameter("targetUri", configuration.getTargetUri());  

Alternatives

This servlet is intentionally simple and limited in scope. As such it may not meet your needs, so consider looking at these alternatives:

Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. "Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below). "Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof. "Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution." "Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by Licensor and subsequently incorporated within the Work. 2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form. 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. 4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions: (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and (b) You must cause any modified files to carry prominent notices stating that You changed the files; and (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License. You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License. 5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions. 6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file. 7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License. 8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages. 9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives. Copyright [yyyy] [name of copyright owner] Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

简介

暂无描述 展开 收起
Apache-2.0
取消

发行版

暂无发行版

贡献者

全部

近期动态

不能加载更多了
马建仓 AI 助手
尝试更多
代码解读
代码找茬
代码优化
1
https://gitee.com/hlzha/HTTP-Proxy-Servlet.git
git@gitee.com:hlzha/HTTP-Proxy-Servlet.git
hlzha
HTTP-Proxy-Servlet
HTTP-Proxy-Servlet
master

搜索帮助