com.google.devtools.build.lib.webstatusserver.StaticResourceHandler.java Source code

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Here is the source code for com.google.devtools.build.lib.webstatusserver.StaticResourceHandler.java

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// Copyright 2014 Google Inc. All rights reserved.
//
// 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.

package com.google.devtools.build.lib.webstatusserver;

import com.google.common.collect.ImmutableList;
import com.google.common.io.CharStreams;
import com.google.devtools.build.lib.util.ResourceFileLoader;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.List;

/**
 * Handler for static resources (JS, html, css...)
 */
public class StaticResourceHandler implements HttpHandler {
    private String response;
    private List<String> contentType;
    private int httpCode;

    public static StaticResourceHandler createFromAbsolutePath(String path, String contentType) {
        return new StaticResourceHandler(path, contentType, true);
    }

    public static StaticResourceHandler createFromRelativePath(String path, String contentType) {
        return new StaticResourceHandler(path, contentType, false);
    }

    private StaticResourceHandler(String path, String contentType, boolean absolutePath) {
        try {
            if (absolutePath) {
                InputStream resourceStream = loadFromAbsolutePath(WebStatusServerModule.class, path);
                response = CharStreams.toString(new InputStreamReader(resourceStream));

            } else {
                response = ResourceFileLoader.loadResource(WebStatusServerModule.class, path);
            }
            httpCode = 200;
        } catch (IOException e) {
            throw new IllegalArgumentException("resource " + path + " not found");
        }
        this.contentType = ImmutableList.of(contentType);
    }

    @Override
    public void handle(HttpExchange exchange) throws IOException {
        exchange.getResponseHeaders().put("Content-Type", contentType);
        exchange.sendResponseHeaders(httpCode, response.length());
        try (OutputStream os = exchange.getResponseBody()) {
            os.write(response.getBytes(StandardCharsets.UTF_8));
        }
    }

    public static InputStream loadFromAbsolutePath(Class<?> loadingClass, String path) throws IOException {
        URL resourceUrl = loadingClass.getClassLoader().getResource(path);
        if (resourceUrl == null) {
            throw new IllegalArgumentException("resource " + path + " not found");
        }
        return resourceUrl.openStream();
    }
}