tryToLoadClass() — netty Function Reference

Architecture documentation for the tryToLoadClass() function in NativeLibraryLoader.java from the netty codebase.

Function java CommonUtil Internal calls 1 called by 1

Entity Profile

CommonUtil→ Internal→ tryToLoadClass() — netty Function Reference

Dependency Diagram

graph TD
  ad07e32d_733a_fab6_069d_362602f3f820["tryToLoadClass()"]
  e940cc67_3be6_5ff3_e560_4d68972dc13b["NativeLibraryLoader"]
  ad07e32d_733a_fab6_069d_362602f3f820 -->|defined in| e940cc67_3be6_5ff3_e560_4d68972dc13b
  bafe3f15_b0bf_647a_3a35_cd885f9d3174["loadLibrary()"]
  bafe3f15_b0bf_647a_3a35_cd885f9d3174 -->|calls| ad07e32d_733a_fab6_069d_362602f3f820
  b457bef5_b901_945e_103b_a802b8d26790["classToByteArray()"]
  ad07e32d_733a_fab6_069d_362602f3f820 -->|calls| b457bef5_b901_945e_103b_a802b8d26790
  style ad07e32d_733a_fab6_069d_362602f3f820 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

common/src/main/java/io/netty/util/internal/NativeLibraryLoader.java lines 447–480

    private static Class<?> tryToLoadClass(final ClassLoader loader, final Class<?> helper)
            throws ClassNotFoundException {
        try {
            return Class.forName(helper.getName(), false, loader);
        } catch (ClassNotFoundException e1) {
            if (loader == null) {
                // cannot defineClass inside bootstrap class loader
                throw e1;
            }
            try {
                // The helper class is NOT found in target ClassLoader, we have to define the helper class.
                final byte[] classBinary = classToByteArray(helper);
                return AccessController.doPrivileged(new PrivilegedAction<Class<?>>() {
                    @Override
                    public Class<?> run() {
                        try {
                            // Define the helper class in the target ClassLoader,
                            //  then we can call the helper to load the native library.
                            Method defineClass = ClassLoader.class.getDeclaredMethod("defineClass", String.class,
                                    byte[].class, int.class, int.class);
                            defineClass.setAccessible(true);
                            return (Class<?>) defineClass.invoke(loader, helper.getName(), classBinary, 0,
                                    classBinary.length);
                        } catch (Exception e) {
                            throw new IllegalStateException("Define class failed!", e);
                        }
                    }
                });
            } catch (ClassNotFoundException | RuntimeException | Error e2) {
                ThrowableUtil.addSuppressed(e2, e1);
                throw e2;
            }
        }
    }