Java tutorial
/* * Copyright (C) 2014 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 com.android.emailcommon.mail; import android.util.Base64; import android.util.Base64OutputStream; import org.apache.commons.io.IOUtils; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; public class Base64Body implements Body { private final InputStream mSource; // Because we consume the input stream, we can only write out once private boolean mAlreadyWritten; public Base64Body(InputStream source) { mSource = source; } @Override public InputStream getInputStream() throws MessagingException { return mSource; } /** * This method consumes the input stream, so can only be called once * @param out Stream to write to * @throws IllegalStateException If called more than once * @throws IOException * @throws MessagingException */ @Override public void writeTo(OutputStream out) throws IllegalStateException, IOException, MessagingException { if (mAlreadyWritten) { throw new IllegalStateException("Base64Body can only be written once"); } mAlreadyWritten = true; try { final Base64OutputStream b64out = new Base64OutputStream(out, Base64.DEFAULT); IOUtils.copyLarge(mSource, b64out); } finally { mSource.close(); } } }