【发布时间】：2016-10-21 15:47:57
【问题描述】：
使用 Inno Setup 安装我的 Java 应用程序时，我希望安装程序检查是否存在 Java 7 或更高版本，并在需要时安装它。但显然，我当前的代码无法在我的一些客户的计算机上检测到 Java 8。不过，我无法重现该错误。你看到我可能遗漏的东西了吗？也许这段代码不适用于最近的 Windows？
基本上，我只是检查 Java >= 1.7 的注册表。
[Code]
function InitializeSetup(): Boolean;
var
ErrorCode: Integer;
JavaInstalled : Boolean;
ResultMsg : Boolean;
Versions: TArrayOfString;
I: Integer;
regRoot: Integer;
begin
{ Check which view of registry should be taken: }
regRoot := HKLM
begin
if IsWin64 then
begin
regRoot := HKLM64
end;
end;
if (RegGetSubkeyNames(regRoot, 'SOFTWARE\JavaSoft\Java Runtime Environment', Versions)) or (RegGetSubkeyNames(regRoot, 'SOFTWARE\JavaSoft\Java Development Kit', Versions)) then
begin
for I := 0 to GetArrayLength(Versions)-1 do
if JavaInstalled = true then
begin
//do nothing
end else
begin
if ( Versions[I][2]='.' ) and ( ( StrToInt(Versions[I][1]) > 1 ) or ( ( StrToInt(Versions[I][1]) = 1 ) and ( StrToInt(Versions[I][3]) >= 7 ) ) ) then
begin
JavaInstalled := true;
end else
begin
JavaInstalled := false;
end;
end;
end else
begin
JavaInstalled := false;
end;
if JavaInstalled then
begin
Result := true;
end else
begin
ResultMsg := MsgBox(ExpandConstant('{cm:JavaRequired}'), mbConfirmation, MB_YESNO) = idYes;
if ResultMsg = false then
begin
Result := false;
end else
begin
Result := true;
ShellExec('open', 'http://www.java.com/getjava/', '','',SW_SHOWNORMAL,ewNoWait,ErrorCode);
end;
end;
end;
编辑：这是基于 Martin 回答的最终结果。
[Code]
function CutJavaVersionPart(var V: string): Integer;
var
S: string;
P: Integer;
begin
if Length(V) = 0 then
begin
Result := 0;
end
else
begin
P := Pos('.', V);
if P = 0 then P := Pos('_', V);
if P > 0 then
begin
S := Copy(V, 1, P - 1);
Delete(V, 1, P);
end
else
begin
S := V;
V := '';
end;
Result := StrToIntDef(S, 0);
end;
end;
function MaxJavaVersion(V1, V2: string): string;
var
Part1, Part2: Integer;
Buf1, Buf2: string;
begin
Buf1 := V1;
Buf2 := V2;
Result := '';
while (Result = '') and
((Buf1 <> '') or (Buf2 <> '')) do
begin
Part1 := CutJavaVersionPart(Buf1);
Part2 := CutJavaVersionPart(Buf2);
if Part1 > Part2 then Result := V1
else
if Part2 > Part1 then Result := V2;
end;
end;
function GetJavaVersion(): string;
var
TempFile: string;
ResultCode: Integer;
S: AnsiString;
P: Integer;
begin
TempFile := ExpandConstant('{tmp}\javaversion.txt');
if (not ExecAsOriginalUser(
ExpandConstant('{cmd}'), '/c java -version 2> "' + TempFile + '"', '',
SW_HIDE, ewWaitUntilTerminated, ResultCode)) or
(ResultCode <> 0) then
begin
Log('Failed to execute java -version');
end
else
if not LoadStringFromFile(TempFile, S) then
begin
Log(Format('Error reading file %s', [TempFile]));
end
else
if Copy(S, 1, 14) <> 'java version "' then
begin
Log('Output of the java -version not as expected');
end
else
begin
Delete(S, 1, 14);
P := Pos('"', S);
if P = 0 then
begin
Log('Output of the java -version not as expected');
end
else
begin
SetLength(S, P - 1);
Result := S;
end;
end;
DeleteFile(TempFile);
end;
function HasJava1Dot7OrNewer: Boolean;
begin
Result := (MaxJavaVersion('1.6.9', GetJavaVersion) <> '1.6.9');
end;
function InitializeSetup(): Boolean;
var
ErrorCode: Integer;
begin
Result := HasJava1Dot7OrNewer;
if not Result then
begin
Result := MsgBox(ExpandConstant('{cm:JavaRequired}'), mbConfirmation, MB_YESNO) = idYes;
if Result then
begin
ShellExec(
'open', 'https://www.java.com/getjava/', '', '', SW_SHOWNORMAL, ewNoWait, ErrorCode);
end;
end;
end;
【问题讨论】：
-
有人更新了这段代码以使用新的 Java 版本控制方案和 OpenJDK 版本吗？
标签： java inno-setup