greedy input handler; will consume stdin completely for unattended builds.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@306851 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/input/GreedyInputHandler.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2005 The Apache Software Foundation
+ *
+ *  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 org.apache.tools.ant.input;
+
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.ByteArrayOutputStream;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.taskdefs.StreamPumper;
+import org.apache.tools.ant.util.FileUtils;
+
+/**
+ * Prompts on System.err, reads input from System.in until EOF
+ *
+ * @since Ant 1.7
+ */
+public class GreedyInputHandler extends DefaultInputHandler {
+
+    private static final int BUFFER_SIZE = 1024;
+
+    /**
+     * Empty no-arg constructor
+     */
+    public GreedyInputHandler() {
+    }
+
+    /**
+     * Prompts and requests input.
+     * @param request the request to handle
+     * @throws BuildException if not possible to read from console,
+     *         or if input is invalid.
+     */
+    public void handleInput(InputRequest request) throws BuildException {
+        String prompt = getPrompt(request);
+        InputStream in = null;
+        try {
+            in = getInputStream();
+            System.err.println(prompt);
+            System.err.flush();
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            StreamPumper p = new StreamPumper(in, baos);
+            Thread t = new Thread(p);
+            t.start();
+            try {
+                t.join();
+            } catch (InterruptedException e) {
+                try {
+                    t.join();
+                } catch (InterruptedException e2) {
+                }
+            }
+            request.setInput(new String(baos.toByteArray()));
+            if (!(request.isInputValid())) {
+                throw new BuildException(
+                    "Received invalid console input");
+            }
+            if (p.getException() != null) {
+                throw new BuildException(
+                    "Failed to read input from console", p.getException());
+            }
+        } finally {
+            FileUtils.close(in);
+        }
+    }
+}