Implemented Files.writeString MCR (#53)

* Implement File writeString

* Fix bugs

Author: AlexProgrammerDE

src/main/java/net/raphimc/javadowngrader/transformer/j10/Java11ToJava10.java

@@ -36,6 +36,7 @@ public Java11ToJava10() {
         this.addMethodCallReplacer(Opcodes.INVOKEVIRTUAL, "java/lang/String", "stripTrailing", "()Ljava/lang/String;", new StringStripTrailingMCR());
 
         this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/nio/file/Files", "readString", new FilesReadStringMCR());
+        this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/nio/file/Files", "writeString", new FilesWriteStringMCR());
 
         this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/nio/file/Path", "of", new PathOfMCR());
 

src/main/java/net/raphimc/javadowngrader/transformer/j10/methodcallreplacer/FilesWriteStringMCR.java

@@ -0,0 +1,70 @@
+/*
+ * This file is part of JavaDowngrader - https://github.com/RaphiMC/JavaDowngrader
+ * Copyright (C) 2023-2024 RK_01/RaphiMC and contributors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package net.raphimc.javadowngrader.transformer.j10.methodcallreplacer;
+
+import net.raphimc.javadowngrader.RuntimeDepCollector;
+import net.raphimc.javadowngrader.transformer.DowngradeResult;
+import net.raphimc.javadowngrader.transformer.MethodCallReplacer;
+import net.raphimc.javadowngrader.util.ASMUtil;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.*;
+
+public class FilesWriteStringMCR implements MethodCallReplacer {
+
+    @Override
+    public InsnList getReplacement(ClassNode classNode, MethodNode methodNode, String originalName, String originalDesc, RuntimeDepCollector depCollector, DowngradeResult result) {
+        int freeVarIndex = ASMUtil.getFreeVarIndex(methodNode);
+        final InsnList replacement = new InsnList();
+
+        boolean hasStoredCharset;
+        if (originalDesc.equals("(Ljava/nio/file/Path;Ljava/lang/CharSequence;[Ljava/nio/file/OpenOption;)Ljava/nio/file/Path;")) {
+            hasStoredCharset = false;
+        } else if (originalDesc.equals("(Ljava/nio/file/Path;Ljava/lang/CharSequence;Ljava/nio/charset/Charset;[Ljava/nio/file/OpenOption;)Ljava/nio/file/Path;")) {
+            hasStoredCharset = true;
+            // Path CharSequence Charset OpenOption
+            replacement.add(new InsnNode(Opcodes.SWAP));
+            // Path CharSequence OpenOption Charset
+            replacement.add(new VarInsnNode(Opcodes.ASTORE, freeVarIndex));
+            // Path CharSequence OpenOption
+        } else {
+            throw new RuntimeException("Unsupported method descriptor: " + originalDesc);
+        }
+
+        // Path CharSequence OpenOption
+        replacement.add(new InsnNode(Opcodes.SWAP));
+        // Path OpenOption CharSequence
+        replacement.add(new MethodInsnNode(Opcodes.INVOKEINTERFACE, "java/lang/CharSequence", "toString", "()Ljava/lang/String;"));
+        // Path OpenOption String
+        if (hasStoredCharset) {
+            replacement.add(new VarInsnNode(Opcodes.ALOAD, freeVarIndex));
+            // Path OpenOption String Charset
+        } else {
+            replacement.add(new FieldInsnNode(Opcodes.GETSTATIC, "java/nio/charset/StandardCharsets", "UTF_8", "Ljava/nio/charset/Charset;"));
+            // Path OpenOption String Charset
+        }
+        replacement.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, "java/lang/String", "getBytes", "(Ljava/nio/charset/Charset;)[B"));
+        // Path OpenOption byte[]
+        replacement.add(new InsnNode(Opcodes.SWAP));
+        // Path byte[] OpenOption
+        replacement.add(new MethodInsnNode(Opcodes.INVOKESTATIC, "java/nio/file/Files", "write", "(Ljava/nio/file/Path;[B[Ljava/nio/file/OpenOption;)Ljava/nio/file/Path;"));
+        // Path
+
+        return replacement;
+    }
+
+}