Java tutorial
/* * Copyright (C) 2010 The Android Open Source Project * * 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 android.webkit; import android.annotation.NonNull; import android.annotation.SystemApi; import android.annotation.UnsupportedAppUsage; import java.io.InputStream; import java.io.StringBufferInputStream; import java.util.Map; /** * Encapsulates a resource response. Applications can return an instance of this * class from {@link WebViewClient#shouldInterceptRequest} to provide a custom * response when the WebView requests a particular resource. */ public class WebResourceResponse { @UnsupportedAppUsage private boolean mImmutable; private String mMimeType; private String mEncoding; @UnsupportedAppUsage private int mStatusCode; private String mReasonPhrase; private Map<String, String> mResponseHeaders; private InputStream mInputStream; /** * Constructs a resource response with the given MIME type, character encoding, * and input stream. Callers must implement {@link InputStream#read(byte[])} for * the input stream. {@link InputStream#close()} will be called after the WebView * has finished with the response. * * <p class="note"><b>Note:</b> The MIME type and character encoding must * be specified as separate parameters (for example {@code "text/html"} and * {@code "utf-8"}), not a single value like the {@code "text/html; charset=utf-8"} * format used in the HTTP Content-Type header. Do not use the value of a HTTP * Content-Encoding header for {@code encoding}, as that header does not specify a * character encoding. Content without a defined character encoding (for example * image resources) should pass {@code null} for {@code encoding}. * * @param mimeType the resource response's MIME type, for example {@code "text/html"}. * @param encoding the resource response's character encoding, for example {@code "utf-8"}. * @param data the input stream that provides the resource response's data. Must not be a * StringBufferInputStream. */ public WebResourceResponse(String mimeType, String encoding, InputStream data) { mMimeType = mimeType; mEncoding = encoding; setData(data); } /** * Constructs a resource response with the given parameters. Callers must implement * {@link InputStream#read(byte[])} for the input stream. {@link InputStream#close()} will be * called after the WebView has finished with the response. * * * <p class="note"><b>Note:</b> See {@link #WebResourceResponse(String,String,InputStream)} * for details on what should be specified for {@code mimeType} and {@code encoding}. * * @param mimeType the resource response's MIME type, for example {@code "text/html"}. * @param encoding the resource response's character encoding, for example {@code "utf-8"}. * @param statusCode the status code needs to be in the ranges [100, 299], [400, 599]. * Causing a redirect by specifying a 3xx code is not supported. * @param reasonPhrase the phrase describing the status code, for example "OK". Must be * non-empty. * @param responseHeaders the resource response's headers represented as a mapping of header * name -> header value. * @param data the input stream that provides the resource response's data. Must not be a * StringBufferInputStream. */ public WebResourceResponse(String mimeType, String encoding, int statusCode, @NonNull String reasonPhrase, Map<String, String> responseHeaders, InputStream data) { this(mimeType, encoding, data); setStatusCodeAndReasonPhrase(statusCode, reasonPhrase); setResponseHeaders(responseHeaders); } /** * Sets the resource response's MIME type, for example "text/html". * * @param mimeType The resource response's MIME type */ public void setMimeType(String mimeType) { checkImmutable(); mMimeType = mimeType; } /** * Gets the resource response's MIME type. * * @return The resource response's MIME type */ public String getMimeType() { return mMimeType; } /** * Sets the resource response's encoding, for example "UTF-8". This is used * to decode the data from the input stream. * * @param encoding The resource response's encoding */ public void setEncoding(String encoding) { checkImmutable(); mEncoding = encoding; } /** * Gets the resource response's encoding. * * @return The resource response's encoding */ public String getEncoding() { return mEncoding; } /** * Sets the resource response's status code and reason phrase. * * @param statusCode the status code needs to be in the ranges [100, 299], [400, 599]. * Causing a redirect by specifying a 3xx code is not supported. * @param reasonPhrase the phrase describing the status code, for example "OK". Must be * non-empty. */ public void setStatusCodeAndReasonPhrase(int statusCode, @NonNull String reasonPhrase) { checkImmutable(); if (statusCode < 100) throw new IllegalArgumentException("statusCode can't be less than 100."); if (statusCode > 599) throw new IllegalArgumentException("statusCode can't be greater than 599."); if (statusCode > 299 && statusCode < 400) throw new IllegalArgumentException("statusCode can't be in the [300, 399] range."); if (reasonPhrase == null) throw new IllegalArgumentException("reasonPhrase can't be null."); if (reasonPhrase.trim().isEmpty()) throw new IllegalArgumentException("reasonPhrase can't be empty."); for (int i = 0; i < reasonPhrase.length(); i++) { int c = reasonPhrase.charAt(i); if (c > 0x7F) { throw new IllegalArgumentException("reasonPhrase can't contain non-ASCII characters."); } } mStatusCode = statusCode; mReasonPhrase = reasonPhrase; } /** * Gets the resource response's status code. * * @return The resource response's status code. */ public int getStatusCode() { return mStatusCode; } /** * Gets the description of the resource response's status code. * * @return The description of the resource response's status code. */ public String getReasonPhrase() { return mReasonPhrase; } /** * Sets the headers for the resource response. * * @param headers Mapping of header name -> header value. */ public void setResponseHeaders(Map<String, String> headers) { checkImmutable(); mResponseHeaders = headers; } /** * Gets the headers for the resource response. * * @return The headers for the resource response. */ public Map<String, String> getResponseHeaders() { return mResponseHeaders; } /** * Sets the input stream that provides the resource response's data. Callers * must implement {@link InputStream#read(byte[])}. {@link InputStream#close()} * will be called after the WebView has finished with the response. * * @param data the input stream that provides the resource response's data. Must not be a * StringBufferInputStream. */ public void setData(InputStream data) { checkImmutable(); // If data is (or is a subclass of) StringBufferInputStream if (data != null && StringBufferInputStream.class.isAssignableFrom(data.getClass())) { throw new IllegalArgumentException( "StringBufferInputStream is deprecated and must " + "not be passed to a WebResourceResponse"); } mInputStream = data; } /** * Gets the input stream that provides the resource response's data. * * @return The input stream that provides the resource response's data */ public InputStream getData() { return mInputStream; } /** * The internal version of the constructor that doesn't perform arguments checks. * @hide */ @SystemApi public WebResourceResponse(boolean immutable, String mimeType, String encoding, int statusCode, String reasonPhrase, Map<String, String> responseHeaders, InputStream data) { mImmutable = immutable; mMimeType = mimeType; mEncoding = encoding; mStatusCode = statusCode; mReasonPhrase = reasonPhrase; mResponseHeaders = responseHeaders; mInputStream = data; } private void checkImmutable() { if (mImmutable) throw new IllegalStateException("This WebResourceResponse instance is immutable"); } }