Windows: "find_java" exe and lib for android.bat

This adds a "find_java.exe" that will be packages
in SDK/tools/lib. It will be used by android.bat
and the other launchers to locate the best version
of java to use for our tools (currently we have
a find_java.bat that uses DOS commands to achieve
something similar but more limited).

In addition this creates a static "findjavalib"
that is used by the NSIS installer to locate
java and get its version (to complain in case we
only find a Java 1.4 or lesser). The goal is for
the installer to use the same logic as the tools
will use to locate the java binary.

Change-Id: Ic2efb388135087bab9687c3332882047fd041b1c
diff --git a/find_java/find_java_exe.cpp b/find_java/find_java_exe.cpp
new file mode 100644
index 0000000..74f8ac1
--- /dev/null
+++ b/find_java/find_java_exe.cpp
@@ -0,0 +1,133 @@
+/*

+ * Copyright (C) 2012 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.

+ */

+

+/*

+ * "find_java.exe", for Windows only.

+ * Tries to find a Java binary in a variety of places and prints the

+ * first one found on STDOUT and returns 0.

+ *

+ * If not found, returns error 1 with no message

+ * (unless ANDROID_SDKMAN_DEBUG or -d if set, in which case there's a message on STDERR).

+ *

+ * Implementation details:

+ * - We don't have access to ATL or MFC.

+ * - We don't want to pull in things like STL.

+ * - No Unicode/MBCS support for now.

+ *

+ * TODO for later version:

+ * - provide an env variable to let users override which version is being used.

+ * - if there's more than one java.exe found, enumerate them all.

+ * - and in that case take the one with the highest Java version number.

+ * - since that operation is expensive, do it only once and cache the result

+ *   in a temp file. If the temp file is not found or the java binary no

+ *   longer exists, re-run the enumaration.

+ */

+

+#ifdef _WIN32

+

+#include "utils.h"

+#include "find_java.h"

+#include <io.h>

+#include <fcntl.h>

+

+static void testFindJava() {

+

+    CPath javaPath("<not found>");

+    bool ok = findJavaInEnvPath(&javaPath);

+    printf("findJavaInEnvPath: [%s] %s\n", ok ? "OK" : "FAIL", javaPath.cstr());

+

+    javaPath.set("<not found>");

+    ok = findJavaInRegistry(&javaPath);

+    printf("findJavaInRegistry [%s] %s\n", ok ? "OK" : "FAIL", javaPath.cstr());

+

+    javaPath.set("<not found>");

+    ok = findJavaInProgramFiles(&javaPath);

+    printf("findJavaInProgramFiles [%s] %s\n", ok ? "OK" : "FAIL", javaPath.cstr());

+}

+

+

+int main(int argc, char* argv[]) {

+

+    gIsConsole = true; // tell utils to to print errors to stderr

+    gIsDebug = (getenv("ANDROID_SDKMAN_DEBUG") != NULL);

+    bool doShortPath = false;

+    bool doVersion = false;

+

+    for (int i = 1; i < argc; i++) {

+        if (strncmp(argv[i], "-t", 2) == 0) {

+            testFindJava();

+            return 0;

+

+        } else if (strncmp(argv[i], "-d", 2) == 0) {

+            gIsDebug = true;

+

+        } else if (strncmp(argv[i], "-s", 2) == 0) {

+            doShortPath = true;

+

+        } else if (strncmp(argv[i], "-v", 2) == 0) {

+            doVersion = true;

+

+        } else {

+            printf(

+                "Outputs the path of the first Java.exe found on the local system.\n"

+                "Returns code 0 when found, 1 when not found.\n"

+                "Options:\n"

+                "-h / -help   : This help.\n"

+                "-t / -test   : Internal test.\n"

+                "-s / -short  : Print path in short DOS form.\n"

+                "-v / -version: Only prints the Java version found.\n"

+                );

+            return 2;

+        }

+    }

+

+    CPath javaPath;

+    if (!findJavaInEnvPath(&javaPath) &&

+        !findJavaInRegistry(&javaPath) &&

+        !findJavaInProgramFiles(&javaPath)) {

+            if (gIsDebug) {

+                fprintf(stderr, "Failed to find Java on your system.\n");

+            }

+            return 1;

+    }

+    _ASSERT(!javaPath.isEmpty());

+

+    if (doShortPath) {

+        if (!javaPath.toShortPath(&javaPath)) {

+            fprintf(stderr,

+                "Failed to convert path to a short DOS path: %s\n",

+                javaPath.cstr());

+            return 1;

+        }

+    }

+

+    if (doVersion) {

+        // Print version found

+        CString version;

+        if (getJavaVersion(javaPath, &version)) {

+            printf("%s", version.cstr());

+            return 0;

+        } else {

+            fprintf(stderr, "Failed to get version of %s\n", javaPath.cstr());

+        }

+    }

+

+    // Print java.exe path found

+    printf("%s", javaPath.cstr());

+    return 0;

+}

+

+#endif /* _WIN32 */