First draft of multiple Java installation detection on Windows

gui/settingsdialog.cpp

@@ -185,9 +185,9 @@ void SettingsDialog::loadSettings(SettingsObject *s)
 void SettingsDialog::on_pushButton_clicked()
 {
 	JavaUtils jut;
-	QStringList paths = jut.FindJavaPath();
+	auto javas = jut.FindJavaPaths();
 
-	ui->javaPathTextBox->setText(paths.at(0));
+	ui->javaPathTextBox->setText(std::get<JI_PATH>(javas.at(0)));
 }
 
 void SettingsDialog::on_btnBrowse_clicked()

gui/settingsdialog.ui

@@ -374,6 +374,12 @@
          <layout class="QGridLayout" name="gridLayout_3">
           <item row="0" column="0">
            <widget class="QLabel" name="labelJavaPath">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
             <property name="text">
              <string>Java path:</string>
             </property>
@@ -381,6 +387,12 @@
           </item>
           <item row="2" column="0">
            <widget class="QLabel" name="labelJVMArgs">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
             <property name="text">
              <string>JVM arguments:</string>
             </property>
@@ -402,9 +414,6 @@
           <item row="0" column="1" colspan="3">
            <widget class="QLineEdit" name="javaPathTextBox"/>
           </item>
-          <item row="2" column="1" colspan="3">
-           <widget class="QLineEdit" name="jvmArgsTextBox"/>
-          </item>
           <item row="1" column="2">
            <widget class="QPushButton" name="pushButton">
             <property name="sizePolicy">
@@ -418,6 +427,9 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="1" colspan="3">
+           <widget class="QLineEdit" name="jvmArgsTextBox"/>
+          </item>
          </layout>
         </widget>
        </item>

logic/JavaUtils.cpp

@@ -14,7 +14,6 @@
  */
 
 #include "JavaUtils.h"
-#include "osutils.h"
 #include "pathutils.h"
 
 #include <QStringList>
@@ -22,27 +21,33 @@
 #include <QDir>
 #include <logger/QsLog.h>
 
-#if WINDOWS
-#include <windows.h>
-
-#endif
-
 JavaUtils::JavaUtils()
 {
 
 }
 
-#if WINDOWS
+std::vector<java_install> JavaUtils::GetDefaultJava()
-QStringList JavaUtils::FindJavaPath()
 {
-	QStringList paths;
+	std::vector<java_install> javas;
+	javas.push_back(std::make_tuple("java", "unknown", "java", false));
+
+	return javas;
+}
+
+#if WINDOWS
+std::vector<java_install> JavaUtils::FindJavaFromRegistryKey(DWORD keyType, QString keyName)
+{
+	std::vector<java_install> javas;
+
+	QString archType = "unknown";
+	if(keyType == KEY_WOW64_64KEY) archType = "64";
+	else if(keyType == KEY_WOW64_32KEY) archType = "32";
 
 	HKEY jreKey;
-	QString jreKeyName = "SOFTWARE\\JavaSoft\\Java Runtime Environment";
+	if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, keyName.toStdString().c_str(), 0, KEY_READ | keyType | KEY_ENUMERATE_SUB_KEYS, &jreKey) == ERROR_SUCCESS)
-	if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, jreKeyName.toStdString().c_str(), 0, KEY_READ | KEY_WOW64_64KEY, &jreKey) == ERROR_SUCCESS)
 	{
-		// Read the current JRE version from the registry.
+		// Read the current type version from the registry.
-		// This will be used to find the key that contains the JavaHome value.
+		// This will be used to find any key that contains the JavaHome value.
 		char *value = new char[0];
 		DWORD valueSz = 0;
 		if (RegQueryValueExA(jreKey, "CurrentVersion", NULL, NULL, (BYTE*)value, &valueSz) == ERROR_MORE_DATA)
@@ -51,64 +56,102 @@ QStringList JavaUtils::FindJavaPath()
 			RegQueryValueExA(jreKey, "CurrentVersion", NULL, NULL, (BYTE*)value, &valueSz);
 		}
 
-		RegCloseKey(jreKey);
+		QString recommended = value;
 
-		// Now open the registry key for the JRE version that we just got.
+		TCHAR subKeyName[255];
-		jreKeyName.append("\\").append(value);
+		DWORD subKeyNameSize, numSubKeys, retCode;
-		if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, jreKeyName.toStdString().c_str(), 0, KEY_READ | KEY_WOW64_64KEY, &jreKey) == ERROR_SUCCESS)
+
+		// Get the number of subkeys
+		RegQueryInfoKey(jreKey, NULL, NULL, NULL, &numSubKeys, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
+
+		// Iterate until RegEnumKeyEx fails
+		if(numSubKeys > 0)
 		{
-			// Read the JavaHome value to find where Java is installed.
+			for(int i = 0; i < numSubKeys; i++)
-			value = new char[0];
-			valueSz = 0;
-			if (RegQueryValueExA(jreKey, "JavaHome", NULL, NULL, (BYTE*)value, &valueSz) == ERROR_MORE_DATA)
 			{
-				value = new char[valueSz];
+				subKeyNameSize = 255;
-				RegQueryValueExA(jreKey, "JavaHome", NULL, NULL, (BYTE*)value, &valueSz);
+				retCode = RegEnumKeyEx(jreKey, i, subKeyName, &subKeyNameSize, NULL, NULL, NULL, NULL);
+				if(retCode == ERROR_SUCCESS)
+				{
+					// Now open the registry key for the version that we just got.
+					QString newKeyName = keyName + "\\" + subKeyName;
 
-				paths << QDir(PathCombine(value, "bin")).absoluteFilePath("java.exe");
+					HKEY newKey;
+					if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, newKeyName.toStdString().c_str(), 0, KEY_READ | KEY_WOW64_64KEY, &newKey) == ERROR_SUCCESS)
+					{
+						// Read the JavaHome value to find where Java is installed.
+						value = new char[0];
+						valueSz = 0;
+						if (RegQueryValueEx(newKey, "JavaHome", NULL, NULL, (BYTE*)value, &valueSz) == ERROR_MORE_DATA)
+						{
+							value = new char[valueSz];
+							RegQueryValueEx(newKey, "JavaHome", NULL, NULL, (BYTE*)value, &valueSz);
+
+							javas.push_back(std::make_tuple(subKeyName, archType, QDir(PathCombine(value, "bin")).absoluteFilePath("java.exe"), (recommended == subKeyName)));
+						}
+
+						RegCloseKey(newKey);
+					}
+				}
 			}
-
-			RegCloseKey(jreKey);
 		}
+
+		RegCloseKey(jreKey);
 	}
 
-	if(paths.length() <= 0)
+	return javas;
+}
+
+std::vector<java_install> JavaUtils::FindJavaPaths()
+{			
+	std::vector<java_install> JRE64s = this->FindJavaFromRegistryKey(KEY_WOW64_64KEY, "SOFTWARE\\JavaSoft\\Java Runtime Environment");
+	std::vector<java_install> JDK64s = this->FindJavaFromRegistryKey(KEY_WOW64_64KEY, "SOFTWARE\\JavaSoft\\Java Development Kit");
+	std::vector<java_install> JRE32s = this->FindJavaFromRegistryKey(KEY_WOW64_32KEY, "SOFTWARE\\JavaSoft\\Java Runtime Environment");
+	std::vector<java_install> JDK32s = this->FindJavaFromRegistryKey(KEY_WOW64_32KEY, "SOFTWARE\\JavaSoft\\Java Development Kit");
+
+	std::vector<java_install> javas;
+	javas.insert(javas.end(), JRE64s.begin(), JRE64s.end());
+	javas.insert(javas.end(), JDK64s.begin(), JDK64s.end());
+	javas.insert(javas.end(), JRE32s.begin(), JRE32s.end());
+	javas.insert(javas.end(), JDK32s.begin(), JDK32s.end());
+
+	if(javas.size() <= 0)
 	{
 		QLOG_WARN() << "Failed to find Java in the Windows registry - defaulting to \"java\"";
-		paths << "java";
+		return this->GetDefaultJava();
 	}
 
-	return paths;
+	QLOG_INFO() << "Found the following Java installations (64 -> 32, JRE -> JDK): ";
+
+	for(auto &java : javas)
+	{
+		QString sRec;
+		if(std::get<JI_REC>(java)) sRec = "(Recommended)";
+		QLOG_INFO() << std::get<JI_ID>(java) << std::get<JI_ARCH>(java) << " at " << std::get<JI_PATH>(java) << sRec;
+	}
+
+	return javas;
 }
 #elif OSX
-QStringList JavaUtils::FindJavaPath()
+std::vector<java_install> JavaUtils::FindJavaPath()
 {
 	QLOG_INFO() << "OS X Java detection incomplete - defaulting to \"java\"";
 
-	QStringList paths;
+	return this->GetDefaultPath();
-	paths << "java";
-
-	return paths;
 }
 
 #elif LINUX
-QStringList JavaUtils::FindJavaPath()
+std::vector<java_install> JavaUtils::FindJavaPath()
 {
 	QLOG_INFO() << "Linux Java detection incomplete - defaulting to \"java\"";
 
-	QStringList paths;
+	return this->GetDefaultPath();
-	paths << "java";
-
-	return paths;
 }
 #else
-QStringList JavaUtils::FindJavaPath()
+std::vector<java_install> JavaUtils::FindJavaPath()
 {
 	QLOG_INFO() << "Unknown operating system build - defaulting to \"java\"";
 
-	QStringList paths;
+	return this->GetDefaultPath();
-	paths << "java";
-
-	return paths;
 }
 #endif

logic/JavaUtils.h

@@ -17,10 +17,28 @@
 
 #include <QStringList>
 
+#include "osutils.h"
+
+#if WINDOWS
+	#include <windows.h>
+#endif
+
+#define JI_ID 0
+#define JI_ARCH 1
+#define JI_PATH 2
+#define JI_REC 3
+typedef std::tuple<QString, QString, QString, bool> java_install;
+
 class JavaUtils
 {
 public:
 	JavaUtils();
 
-	QStringList FindJavaPath();
+	std::vector<java_install> FindJavaPaths();
+
+private:
+	std::vector<java_install> GetDefaultJava();
+#if WINDOWS
+	std::vector<java_install> FindJavaFromRegistryKey(DWORD keyType, QString keyName);
+#endif
 };