Initial Commit

Author: Seggan

.gitignore

@@ -0,0 +1,3 @@
+.idea
+target
+JavaClassLib.iml

pom.xml

@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>io.github.seggan.javaclasslib</groupId>
+    <artifactId>JavaClassLib</artifactId>
+    <version>0.1.0</version>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <configuration>
+                    <relocations>
+                        <relocation>
+                            <pattern>com.google.common</pattern>
+                            <shadedPattern>io.github.seggan.javaclasslib.common</shadedPattern>
+                        </relocation>
+                    </relocations>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.0.0-M5</version>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+            <version>3.0.2</version>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>30.1.1-jre</version>
+            <scope>compile</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.6.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

src/main/java/io/github/seggan/javaclasslib/ByteUtils.java

@@ -0,0 +1,38 @@
+package io.github.seggan.javaclasslib;
+
+import javax.annotation.Nonnull;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+public final class ByteUtils {
+
+    private ByteUtils() {}
+
+    @Nonnull
+    public static byte[] twoBytesFromInt(int i) {
+        byte[] data = new byte[2];
+        data[0] = (byte) ((i >> 8) & 0xFF);
+        data[1] = (byte) (i & 0xFF);
+        return data;
+    }
+
+    @Nonnull
+    public static byte[] floatToBytes(float f) {
+        return ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN).putFloat(f).array();
+    }
+
+    @Nonnull
+    public static byte[] intToBytes(int i) {
+        return ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN).putInt(i).array();
+    }
+
+    @Nonnull
+    public static byte[] longToBytes(long l) {
+        return ByteBuffer.allocate(8).order(ByteOrder.BIG_ENDIAN).putLong(l).array();
+    }
+
+    @Nonnull
+    public static byte[] doubleToBytes(double d) {
+        return ByteBuffer.allocate(8).order(ByteOrder.BIG_ENDIAN).putDouble(d).array();
+    }
+}

src/main/java/io/github/seggan/javaclasslib/JavaClass.java

@@ -0,0 +1,11 @@
+package io.github.seggan.javaclasslib;
+
+import io.github.seggan.javaclasslib.constantpool.ConstantPoolEntry;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public final class JavaClass {
+
+    private final List<ConstantPoolEntry> constantPool = new LinkedList<>();
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/ClassEntry.java

@@ -0,0 +1,22 @@
+package io.github.seggan.javaclasslib.constantpool;
+
+import com.google.common.primitives.Bytes;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+
+public final class ClassEntry extends ConstantPoolEntry {
+
+    private final UTF8Entry name;
+
+    public ClassEntry(List<ConstantPoolEntry> constantPool, UTF8Entry name) {
+        super(constantPool, ConstantPoolTag.CLASS);
+        this.name = name;
+    }
+
+    @Nonnull
+    @Override
+    public byte[] getBytes() {
+        return Bytes.concat(getTag().getByte(), name.getIndexBytes());
+    }
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/ConstantPoolEntry.java

@@ -0,0 +1,53 @@
+package io.github.seggan.javaclasslib.constantpool;
+
+import io.github.seggan.javaclasslib.ByteUtils;
+
+import javax.annotation.Nonnull;
+import javax.annotation.ParametersAreNonnullByDefault;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+public abstract class ConstantPoolEntry {
+
+    private final List<ConstantPoolEntry> constantPool;
+    private final ConstantPoolTag tag;
+
+    @ParametersAreNonnullByDefault
+    public ConstantPoolEntry(List<ConstantPoolEntry> constantPool, ConstantPoolTag tag) {
+        this.constantPool = constantPool;
+        this.tag = tag;
+        constantPool.add(this);
+    }
+
+    public final ConstantPoolTag getTag() {
+        return tag;
+    }
+
+    public final int getIndex() {
+        return constantPool.indexOf(this);
+    }
+
+    @Nonnull
+    public final byte[] getIndexBytes() {
+        return ByteUtils.twoBytesFromInt(getIndex());
+    }
+
+    @Nonnull
+    public abstract byte[] getBytes();
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof ConstantPoolEntry)) return false;
+        ConstantPoolEntry that = (ConstantPoolEntry) o;
+        return getTag() == that.getTag() && Arrays.equals(getBytes(), that.getBytes());
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hash(getTag());
+        result = 31 * result + Arrays.hashCode(getBytes());
+        return result;
+    }
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/ConstantPoolTag.java

@@ -0,0 +1,31 @@
+package io.github.seggan.javaclasslib.constantpool;
+
+import javax.annotation.Nonnull;
+
+public enum ConstantPoolTag {
+    CLASS(7),
+    FIELDREF(9),
+    METHODREF(10),
+    INTERFACE_METHODREF(11),
+    STRING(8),
+    INTEGER(3),
+    FLOAT(4),
+    LONG(5),
+    DOUBLE(6),
+    NAME_AND_TYPE(12),
+    UTF_8(1),
+    METHOD_HANDLE(15),
+    METHOD_TYPE(16),
+    INVOKE_DYNAMIC(18);
+
+    private final byte binary;
+
+    ConstantPoolTag(int binary) {
+        this.binary = (byte) binary;
+    }
+
+    @Nonnull
+    public byte[] getByte() {
+        return new byte[]{binary};
+    }
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/NameAndTypeEntry.java

@@ -0,0 +1,24 @@
+package io.github.seggan.javaclasslib.constantpool;
+
+import com.google.common.primitives.Bytes;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+
+public final class NameAndTypeEntry extends ConstantPoolEntry {
+
+    private final UTF8Entry name;
+    private final UTF8Entry descriptor;
+
+    public NameAndTypeEntry(List<ConstantPoolEntry> constantPool, UTF8Entry name, UTF8Entry descriptor) {
+        super(constantPool, ConstantPoolTag.NAME_AND_TYPE);
+        this.name = name;
+        this.descriptor = descriptor;
+    }
+
+    @Nonnull
+    @Override
+    public byte[] getBytes() {
+        return Bytes.concat(getTag().getByte(), name.getIndexBytes(), descriptor.getIndexBytes());
+    }
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/UTF8Entry.java

@@ -0,0 +1,28 @@
+package io.github.seggan.javaclasslib.constantpool;
+
+import com.google.common.primitives.Bytes;
+import io.github.seggan.javaclasslib.ByteUtils;
+
+import javax.annotation.Nonnull;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+
+public final class UTF8Entry extends ConstantPoolEntry {
+
+    private final byte[] data;
+
+    public UTF8Entry(List<ConstantPoolEntry> constantPool, byte[] data) {
+        super(constantPool, ConstantPoolTag.UTF_8);
+        this.data = data;
+    }
+
+    public UTF8Entry(List<ConstantPoolEntry> constantPool, String s) {
+        this(constantPool, s.getBytes(StandardCharsets.UTF_8));
+    }
+
+    @Nonnull
+    @Override
+    public byte[] getBytes() {
+        return Bytes.concat(getTag().getByte(), ByteUtils.twoBytesFromInt(data.length), data);
+    }
+}

src/main/java/io/github/seggan/javaclasslib/constantpool/classmembers/ClassMemberEntry.java

@@ -0,0 +1,28 @@
+package io.github.seggan.javaclasslib.constantpool.classmembers;
+
+import com.google.common.primitives.Bytes;
+import io.github.seggan.javaclasslib.constantpool.ClassEntry;
+import io.github.seggan.javaclasslib.constantpool.ConstantPoolEntry;
+import io.github.seggan.javaclasslib.constantpool.ConstantPoolTag;
+import io.github.seggan.javaclasslib.constantpool.NameAndTypeEntry;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+
+abstract class ClassMemberEntry extends ConstantPoolEntry {
+
+    private final ClassEntry clazz;
+    private final NameAndTypeEntry nameAndType;
+
+    public ClassMemberEntry(List<ConstantPoolEntry> constantPool, ConstantPoolTag key, ClassEntry clazz, NameAndTypeEntry nameAndType) {
+        super(constantPool, key);
+        this.clazz = clazz;
+        this.nameAndType = nameAndType;
+    }
+
+    @Nonnull
+    @Override
+    public final byte[] getBytes() {
+        return Bytes.concat(getTag().getByte(), clazz.getIndexBytes(), nameAndType.getIndexBytes());
+    }
+}