java.lang.ExceptionInInitializerError原因及解决办法

java.lang.Object
↳	java.lang.Throwable
	↳	java.lang.Error
		↳	java.lang.LinkageError
			↳	java.lang.ExceptionInInitializerError

ExceptionInInitializerError 通常意味着在静态初始化块或静态变量初始化过程中发生了异常。

静态代码块异常：如果在静态代码块中有任何异常抛出，都会导致此错误。

public class StaticBlock {

    private static int state;

    static {
        state = 42 / 0; //除0异常
    }
}

静态变量初始化异常：如果静态变量在初始化时抛出了异常，也会导致此错误。（编译后实际上也是在静态代码块里面）

public class Example {
    private static final int number = Integer.parseInt("abc"); // 这里会抛出NumberFormatException
}

解决方法

一般来说，查看堆栈跟踪都能找出问题所在。

1. 检查静态初始化块：确保静态初始化块中没有抛出异常的代码。
2. 检查静态变量初始化：确保所有静态变量的初始化都是安全的，没有抛出异常。

工作中的例子

java.lang.ExceptionInInitializerError at com.xxx.xx.Service.onInit(Service.java:654) 

查看654行代码，引用了一个静态类。

static {
    try {
        String path = "/data/data/com.xxx.xx/lib/libxxplay.so";
        File file = new File(path);
        if (file.exists()) {
            SFLogger.d(TAG, "use /data/data/com.xxx.xx/lib/libxxplay.so");
            System.load(path);
        } else {
            SFLogger.d(TAG, "use /system/lib/libxxplay.so");
            System.loadLibrary("xxplay");
        }
    } catch (Exception e) {
        SFLogger.e(TAG, "JniUtil loadLibrary exception = " + e.getMessage());
    }
}

以上代码咋一看好像也没什么问题啊，异常都catch住了。

但如果仔细研究就会发现，这里的问题是滥用了Exception，没有针对具体异常进行捕获。查看loadLibrary源码发现其可能会抛出SecurityException、UnsatisfiedLinkError或者NullPointerException，SecurityException和NullPointerException的父类都是RuntimeException，是一种异常（Exception），UnsatisfiedLinkError的父类是LinkageError，是一种错误（Error），所以如果这里发生了UnsatisfiedLinkError，通过Exception是捕获不了的，必须通过他们的共同父类Throwable来进行捕获。当然，最好还是针对具体的异常进行捕获，不要用这种扩大化的捕获方式，容易隐藏问题。

    /**
     * Loads the native library specified by the <code>libname</code>
     * argument.  The <code>libname</code> argument must not contain any platform
     * specific prefix, file extension or path. If a native library
     * called <code>libname</code> is statically linked with the VM, then the
     * JNI_OnLoad_<code>libname</code> function exported by the library is invoked.
     * See the JNI Specification for more details.
     *
     * Otherwise, the libname argument is loaded from a system library
     * location and mapped to a native library image in an implementation-
     * dependent manner.
     * <p>
     * The call <code>System.loadLibrary(name)</code> is effectively
     * equivalent to the call
     * <blockquote><pre>
     * Runtime.getRuntime().loadLibrary(name)
     * </pre></blockquote>
     *
     * @param      libname   the name of the library.
     * @exception  SecurityException  if a security manager exists and its
     *             <code>checkLink</code> method doesn't allow
     *             loading of the specified dynamic library
     * @exception  UnsatisfiedLinkError if either the libname argument
     *             contains a file path, the native library is not statically
     *             linked with the VM,  or the library cannot be mapped to a
     *             native library image by the host system.
     * @exception  NullPointerException if <code>libname</code> is
     *             <code>null</code>
     * @see        java.lang.Runtime#loadLibrary(java.lang.String)
     * @see        java.lang.SecurityManager#checkLink(java.lang.String)
     */
    @CallerSensitive
    public static void loadLibrary(String libname) {
        Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
    }

参考

ExceptionInInitializerError | Android Developers

When Does Java Throw the ExceptionInInitializerError? | Baeldung

Chapter 11. Exceptions