测试Unsafe包操作

impl/yaml/src/test/java/config/OffsetTest.java

@@ -0,0 +1,31 @@
+package config;
+
+import config.offset.FieldOffset;
+import config.offset.OffsetUtil;
+import config.source.ComplexConfiguration;
+import org.junit.Test;
+
+import java.util.List;
+
+public class OffsetTest {
+
+    @Test
+    public void test() {
+
+
+        List<FieldOffset> fieldOffsets = OffsetUtil.getClassMemberOffset(ComplexConfiguration.class);
+
+        output(fieldOffsets);
+
+    }
+
+    protected static void output(List<FieldOffset> fieldOffsets) {
+        for (FieldOffset fieldOffset : fieldOffsets) {
+            System.out.println(fieldOffset.getOffsetValue() + " -> " + fieldOffset.getField().getName());
+            if (!fieldOffset.getSubFieldOffsetList().isEmpty()) {
+                output(fieldOffset.getSubFieldOffsetList());
+            }
+        }
+    }
+
+}

impl/yaml/src/test/java/config/offset/FieldOffset.java

@@ -0,0 +1,62 @@
+package config.offset;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Field;
+import java.util.List;
+
+/**
+ * @author Chris2018998
+ */
+public class FieldOffset implements Comparable<FieldOffset> {
+    private final Field field;
+    private Long offsetValue;
+    private List<FieldOffset> subFieldOffsetList;
+
+    public FieldOffset(Field field) {
+        this.field = field;
+    }
+
+    public Long getOffsetValue() {
+        return offsetValue;
+    }
+
+    public void setOffsetValue(Long offsetValue) {
+        this.offsetValue = offsetValue;
+    }
+
+    public String toString() {
+        if (subFieldOffsetList == null)
+            return field.getName();
+        else {
+
+            StringBuilder builder = new StringBuilder();
+            builder.append("[");
+
+            for (int i = 0; i < subFieldOffsetList.size(); i++) {
+                FieldOffset offset = subFieldOffsetList.get(i);
+                if (i > 0) builder.append(",");
+                builder.append(field.getName()).append(".").append(offset.toString());
+            }
+            builder.append("]");
+            return builder.toString();
+        }
+    }
+
+    public List<FieldOffset> getSubFieldOffsetList() {
+        return subFieldOffsetList;
+    }
+
+    public void setSubFieldOffsetList(List<FieldOffset> subFieldOffsetList) {
+        this.subFieldOffsetList = subFieldOffsetList;
+    }
+
+    public Field getField() {
+        return field;
+    }
+
+    @Override
+    public int compareTo(@NotNull FieldOffset that) {
+        return this.offsetValue.compareTo(that.offsetValue);
+    }
+}

impl/yaml/src/test/java/config/offset/OffsetUtil.java

@@ -0,0 +1,55 @@
+package config.offset;
+
+import jdk.internal.misc.Unsafe;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * @author Chris2018998
+ */
+public class OffsetUtil {
+    private static Unsafe unsafe;
+
+    static {
+        try {
+            unsafe = AccessController.doPrivileged((PrivilegedExceptionAction<Unsafe>) () -> {
+                Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
+                theUnsafe.setAccessible(true);
+                return (Unsafe) theUnsafe.get(null);
+            });
+        } catch (Throwable e) {
+            System.err.println("Unable to load unsafe");
+        }
+    }
+
+    public static List<FieldOffset> getClassMemberOffset(Class<?> beanClass) {
+        List<FieldOffset> offsetsList = new LinkedList<>();
+        for (Field field : beanClass.getDeclaredFields()) {
+            FieldOffset fieldOffset = new FieldOffset(field);
+            offsetsList.add(fieldOffset);
+            if (Modifier.isStatic(field.getModifiers()))
+                fieldOffset.setOffsetValue(unsafe.staticFieldOffset(field));
+            else
+                fieldOffset.setOffsetValue(unsafe.objectFieldOffset(field));
+            Class<?> fieldType = field.getType();
+            if (!fieldType.getName().startsWith("java")) {
+                Field[] subfields = fieldType.getDeclaredFields();
+                if (subfields.length > 0) {
+                    fieldOffset.setSubFieldOffsetList(getClassMemberOffset(fieldType));
+                }
+            }
+        }
+
+        Collections.sort(offsetsList);
+        return offsetsList;
+    }
+
+
+}
+