/// <summary>
/// Searches for a Java executable in the specified home folder
/// </summary>
/// <param name="home">The path in which to search for a Java executable</param>
/// <param name="flags">The search options to use to locate a Java installation</param>
/// <returns>Information about the located Java installation</returns>
public static Java GetJava(string home, JavaFlags flags, string version = null)
{
string JNAME = flags.HasFlag(JavaFlags.Legacy) && !flags.HasFlag(JavaFlags.Development) ? JRE : JDK; //the name of the Java installation
string BTYPE = flags.HasFlag(JavaFlags.Development) ? JAVAC : JAVA; //the name of the relevant Java executable
Java output = new Java()
{
development = flags.HasFlag(JavaFlags.Development),
is32bit = flags.HasFlag(JavaFlags.Registry32),
legacy = flags.HasFlag(JavaFlags.Legacy),
home = home,
version = version
}; //the output Java installation information
//checks for the exe file in the path <home>/bin/
string exe = Path.Combine(output.home, "bin", BTYPE);
if (!File.Exists(exe))
{
output.error = $"Failed to locate {exe}.";
if (!string.IsNullOrWhiteSpace(output.version))
{
output.error += $" Try re-installing {JNAME} {output.version}.";
}
output.errtype = 6;
}
else
{
output.exe = exe;
}
return(output); //returns the located installation information
}
/// <summary>
/// Searches for any Java installation, preferring the specified search options
/// </summary>
/// <param name="flags">The search options to prefer when locate a Java installation</param>
/// <param name="locked">The search options specified in the flags which must be used when locating a Java installation</param>
/// <returns>Information about the current located installation</returns>
public static Java SearchJava(JavaFlags flags = JavaFlags.Default, JavaFlags locked = JavaFlags.Default)
{
Java java = GetJava(flags); //try to find a Java installation with the default settings
int[] vals = (int[])Enum.GetValues(typeof(JavaFlags)); //enumerate the flag values
for (int i = 1; i < 1 << vals.Length; i++) //for every combination of flag values...
{
if (java.errtype == 0) //if an installation has already been found, break
{
break;
}
JavaFlags flags2 = flags; //a modified set of search options
for (int j = 0; j < vals.Length; j++) //for every flag
{
//if the flag is not locked and is part of the current combination, toggle it
if (((int)locked & vals[j]) == 0 && (i & vals[j]) != 0)
{
flags2 ^= (JavaFlags)vals[j];
}
}
Java java2 = GetJava(flags2); //try to find a Java installation with the modified sttings
if (java2.errtype == 0 || java2.errtype < java.errtype) //if the new search had better results, store it
{
java = java2;
}
}
return(java); //returns the located installation information
}
/// <summary>
/// Searches for the Java installation with the specified settings
/// </summary>
/// <param name="flags">The search options to use to locate a Java installation</param>
/// <returns>Information about the located Java installation</returns>
public static Java GetJava(JavaFlags flags)
{
string JTYPE = flags.HasFlag(JavaFlags.Legacy) ? flags.HasFlag(JavaFlags.Development) ? JDK : JRE : SE; //the type of Java installation
string JNAME = flags.HasFlag(JavaFlags.Legacy) && !flags.HasFlag(JavaFlags.Development) ? JRE : JDK; //the name of the Java installation
RegistryView VIEW = flags.HasFlag(JavaFlags.Registry32) ? RegistryView.Registry32 : RegistryView.Registry64; //the registry to search in
Java output = new Java()
{
development = flags.HasFlag(JavaFlags.Development),
is32bit = flags.HasFlag(JavaFlags.Registry32),
legacy = flags.HasFlag(JavaFlags.Legacy)
}; //the output Java installation information
//check each property step-by-step, returning error information if the registry key can't be found
//the output.error messages are sufficient as comments lol
RegistryKey key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, VIEW);
if (key == null)
{
output.error = "Windows Registry is not available.";
output.errtype = 1;
}
else
{
RegistryKey javakey = key.OpenSubKey($@"SOFTWARE\JavaSoft\{JTYPE}");
if (javakey == null)
{
output.error = $"Your computer is missing a {JTYPE}. Try installing the latest version.";
output.errtype = 2;
}
else
{
object version = javakey.GetValue("CurrentVersion");
if (version == null)
{
output.error = $"Your computer has some {JTYPE} registry keys but none seem to be installed. Try re-installing a {JTYPE}.";
output.errtype = 3;
}
else
{
output.version = version.ToString();
RegistryKey verkey = javakey.OpenSubKey(output.version);
if (verkey == null)
{
output.error = $"Java {output.version} is marked as your default {JTYPE} version but lacks a complete installation. Try re-installing {JTYPE} {output.version}.";
output.errtype = 4;
}
else
{
object home = verkey.GetValue("JavaHome");
if (home == null)
{
output.error = $"Java {output.version} is marked as your default {JTYPE} version but lacks a JavaHome directory. Try re-installing {JTYPE} {output.version}.";
output.errtype = 5;
}
else
{
output = GetJava(home.ToString(), flags, output.version);
}
}
}
}
}
return(output); //returns the located installation information
}
