在jersey Interceptor中缩小html和js

Question

使用jersey mvc和jsp，所有对html或js文件的请求都通过@Template或Viewable完成。例子；

  @GET
  @Path(JS_URL + "{type}")
  @Template(name = "grid")
  @Produces("application/javascript")
  public Response buildJSGrid(@DefaultValue("") @PathParam("type") String type) {
     Grid grid = new Grid(type);
....
     return Response.ok(grid).build();
  }

其中grid是内部包含纯javascript的grid.jsp文件

<%@ page contentType="application/javascript;charset=UTF-8" language="java" %>

.....

也可能有html和js的其他变体，例如；

@GET
  @Path(FORM_URL + "{type}")
  @Template(name = "form")
  @Produces(MediaType.TEXT_HTML)
  public Response buildAccountForm(@DefaultValue("") @PathParam("type") String type) {
     Form form = new Form(type);
....
     return Response.ok(form).build();
  }

其中表单是表单.jsp里面有 html 和 js

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

...

我需要在发送到客户端之前缩小结果js和html/js，我尝试使用https://code.google.com/archive/p/htmlcompressor/库，但需要将字符串传递给html compressor . compress(input)；

尝试使用WriterInterceptor

public class MinifyJsInterceptor implements WriterInterceptor {
  @Override
  public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
final OutputStream outputStream = context.getOutputStream();
// here need to convert outputStream to InputStream and after to String ?
// result string to htmlCompressor.compress(resultString);
// after that convert result minify string back to resultOutputStream and set to context ?
context.setOutputStream(new GZIPOutputStream(resultOutputStream));

这是正确的方法吗？我不能把输出流转换成字符串，谢谢

-更新

回答问题；html js的意思是在某些jsp中是html标记和js代码

    <div id="form" style="width: 500px; display: none">
      <div class="w2ui-page page-0">
        <div class="w2ui-field">
    </div>....

    <script type="text/javascript">
      var uiElement = (function () {
        var config = {
            onOpen: function (event) {
      event.onComplete = function () {
        $('#formContainer').w2render('form');
      }
     ...
    }());
    </script>

客户端上请求的文件

         $('#tempContainer').load('that file name - also dynamic', function (data, status, xhr) {
           uiElement.init();
           w2ui[layout].content(layout_main, w2ui[uiElement.name]);
         });

你真的在你的资源方法中返回js文件吗？

        some js and html + js files are dynamic build, example;
        grid.jsp contains inside

<%@ page contentType="application/javascript;charset=UTF-8" language="java" %>

          var uiElement = (function () {
            var config = {
              grid: {
                name: ${it.name},
                listUrl:'${it.entityListUrl}',
                formUrl:'${it.entityFormUrl}',
                columns: ${it.columns},
                records: ${it.records},           
}}

有来自资源方法中的 el 表达式和设置的 ${it..} 值

@GET
      @Path(JS_URL + "{type}")
      @Template(name = "grid")
      @Produces("application/javascript")
      public Response buildJSGrid(@DefaultValue("") @PathParam("type") String type) {
         Grid grid = new Grid(type);
    ....
         return Response.ok(grid).build();
      }}

并从客户端调用js“文件”

         $.getScript('dynamic js file name' - it is dynamic too).done(function (script, status, xhr) {
           //console.log(xhr.responseText);
           uiElement.init();
           w2ui[layout].content(layout_main, w2ui[uiElement.name]);
         });



       also some html blocks build dynamic


{ 
     <c:if test="${it.recid != 0}">
          <div class="w2ui-field">
            <label>active:</label>
            <div>
              <input name="active" type="checkbox"/>
            </div>
          </div>
            </c:if>
}

-- 更新描述，网格构建器;

一个资源和一个模板用于构建任何网格，

  @GET
  @Path(GRID + "{type}")
  @Template(name = W2UI_VIEW_PREFIX + "grid/grid")
  @Produces(MEDIA_TYPE_APPLICATION_JAVASCRIPT)
  public Response buildGrid(@DefaultValue("") @PathParam("type") String type) {
    for (W2UI ui : W2UI.values()) {
      if (type.equals(ui.getName())) {
        W2UIElement grid = ui.getUI();
        return Response.ok(grid).build();
      }
    }
    return Response.noContent().build();
  }

也可以通过Viewable（模板、模型）使用不同的模板（jsp文件）

菜单生成器中的某个位置。jsp模板

List<MenuItem> items..
MenuItem item1 = new MenuItem(W2UI.TASK_GRID, W2UIService.GRID);
items.add(item1);

在哪里

W2UIService.GRID is string url for client js request and for server method resource @Path() anno.

和

public enum W2UI {
  TASK_GRID("task_grid", "tasks", Type.SCRIPT){
    @Override
    public W2UIElement getUI() {
      return new TaskGrid(getName());
    }
  },
.....
}

TaskGrid是用js代码填充grid.jsp模板的模型，所以很容易添加任何类型的网格和不同的数据集和按钮。

组件类型(类型。脚本)在客户端上的处理。getScript()，Type.HTML by $(' # temp container ')。负载()

---更新工厂和供应商；

@Provider
@Priority(200)
@HtmlMinify
public class HtmlMinifyInterceptor implements WriterInterceptor {
  @Inject private HtmlCompressor compressor;

...

public class HtmlMinifierFactory implements Factory<HtmlCompressor> {
  private HtmlCompressor compressor;

  @Override
  public HtmlCompressor provide() {
    if (null == compressor) compressor = new HtmlCompressor();
    ClosureJavaScriptCompressor jsCompressor = new ClosureJavaScriptCompressor();
    jsCompressor.setCompilationLevel(CompilationLevel.SIMPLE_OPTIMIZATIONS);

…

@ApplicationPath("/")
public class MainRsConfig extends ResourceConfig {
  public MainRsConfig() {
..
    register(new AbstractBinder() {
      @Override
      protected void configure() {
        bindFactory(HtmlMinifierFactory.class).to(HtmlCompressor.class).in(Singleton.class);
      }
    });
..




Answer 1

匿名用户

您可以使用ByteArrayOutputStream的自定义实现作为< code > writerceptorcontext 的< code>OutputStream的包装:

import com.googlecode.htmlcompressor.compressor.Compressor;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class HtmlMinifyOutputStream extends ByteArrayOutputStream {

    private OutputStream origOut;
    private Compressor compressor;

    public HtmlMinifyOutputStream(OutputStream origOut, Compressor compressor) {
        this.origOut = origOut;
        this.compressor = compressor;
    }

    public void close() throws IOException {
        super.close();
        String compressedBody = compressor.compress(new String(this.buf));
        this.origOut.write(compressedBody.getBytes());
        this.origOut.close();
    }
}

HtmlMinifyOutputStream可用于WriterInterceptor实现。注入了HtmlCompressor实例：

import com.googlecode.htmlcompressor.compressor.Compressor;
import javax.inject.Inject;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.ext.Provider;
import javax.ws.rs.ext.WriterInterceptor;
import javax.ws.rs.ext.WriterInterceptorContext;
import java.io.*;

@Provider
@HtmlMinify
public class MinifyHtmlInterceptor implements WriterInterceptor {

    @Inject
    private Compressor compressor;

    @Override
    public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
        final OutputStream outputStream = context.getOutputStream();
        context.setOutputStream(new HtmlMinifyOutputStream(outputStream, compressor));
        context.proceed();
    }
}

@HtmlMinify是一个NameBinding注释，用于激活特定资源方法上的MinifyHtmlInterceptor。（请参见https://jersey.java.net/documentation/latest/filters-and-interceptors.html#d0e9988):

import javax.ws.rs.NameBinding;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@NameBinding
@Retention(value = RetentionPolicy.RUNTIME)
public @interface HtmlMinify {}

每个应用程序只能创建一次< code>HtmlCompressor并同时使用，因为:

HtmlCompressor和XmlCompressor类被认为是线程安全的*，可以在多线程环境中使用< br > < I >(https://code . Google . com/archive/p/html compressor/)

下面是一个HK2工厂(请参见:实现定制注入提供程序),它创建压缩器实例并启用内联css和javascript压缩:

import com.googlecode.htmlcompressor.compressor.Compressor;
import com.googlecode.htmlcompressor.compressor.HtmlCompressor;
import org.glassfish.hk2.api.Factory;

public class HtmlCompressorFactory implements Factory<Compressor> {

    private HtmlCompressor compressor;

    @Override
    public Compressor provide() {
        if(compressor == null) {
            compressor = new HtmlCompressor();
        }
        compressor.setCompressJavaScript(true);
        compressor.setCompressCss(true);
        return compressor;
    }

    @Override
    public void dispose(Compressor compressor) {}
}

工厂是用AbstractBinder注册的:

final ResourceConfig rc = new ResourceConfig().packages("com.example");
rc.register(new AbstractBinder() {
    @Override
    protected void configure() {
        bindFactory(HtmlCompressorFactory.class).to(Compressor.class).in(Singleton.class);
    }
});

如果启用了内联脚本或内联 css 压缩：

具有默认设置的超文本标记语言压缩器不需要任何依赖项。
内联CSS压缩需要YUI压缩器库。
内联JavaScript压缩需要YUI压缩器库（默认情况下）或谷歌闭包编译器库。
（https://code.google.com/archive/p/htmlcompressor/）

我使用maven，因此我将此依赖项添加到pom.xml中：

<dependency>
    <groupId>com.yahoo.platform.yui</groupId>
    <artifactId>yuicompressor</artifactId>
    <version>2.4.8</version>
</dependency>

如果要使用Google Closure Compiler，请使用以下依赖项：

<dependency>
    <groupId>com.google.javascript</groupId>
    <artifactId>closure-compiler</artifactId>
    <version>r2388</version>
</dependency>

并激活它：

compressor.setJavaScriptCompressor(new ClosureJavaScriptCompressor());
compressor.setCompressJavaScript(true);
compressor.setCssCompressor(new YuiCssCompressor());
compressor.setCompressCss(true);
return compressor;

如果要压缩纯JavaScript或CSS文件，则不能使用< code>htmlcompressor。这个库只支持内嵌CSS/JS的HTML文件。但是您可以实现一个类似于< code>MinifyJsInterceptor的< code > minifycss interceptor ，它直接使用YUI压缩器和/或Google闭包库。

对于 gzip 压缩，您应该实现另一个拦截器。因此，可以单独配置缩小和压缩。如果激活多个拦截器，请使用 javax.annotation.优先级来控制执行顺序。（请参阅：https://jersey.java.net/documentation/latest/filters-and-interceptors.html#d0e9927）