只要使用任何一个NoException(我的项目)，jOOλ的Unchecked, throw -lambdas, Throwable接口或Faux Pas。

// NoException
stream.map(Exceptions.sneak().function(Class::forName));

// jOOλ
stream.map(Unchecked.function(Class::forName));

// throwing-lambdas
stream.map(Throwing.function(Class::forName).sneakyThrow());

// Throwable interfaces
stream.map(FunctionWithThrowable.aFunctionThatUnsafelyThrowsUnchecked(Class::forName));

// Faux Pas
stream.map(FauxPas.throwingFunction(Class::forName));

这个LambdaExceptionUtil帮助类允许你在Java流中使用任何受控异常，像这样:

Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String")
      .map(rethrowFunction(Class::forName))
      .collect(Collectors.toList());

注意:Class::forName抛出ClassNotFoundException，该异常被检查。流本身也会抛出ClassNotFoundException和NOT一些未检查的包装异常。

public final class LambdaExceptionUtil {

@FunctionalInterface
public interface Consumer_WithExceptions<T, E extends Exception> {
    void accept(T t) throws E;
    }

@FunctionalInterface
public interface BiConsumer_WithExceptions<T, U, E extends Exception> {
    void accept(T t, U u) throws E;
    }

@FunctionalInterface
public interface Function_WithExceptions<T, R, E extends Exception> {
    R apply(T t) throws E;
    }

@FunctionalInterface
public interface Supplier_WithExceptions<T, E extends Exception> {
    T get() throws E;
    }

@FunctionalInterface
public interface Runnable_WithExceptions<E extends Exception> {
    void run() throws E;
    }

/** .forEach(rethrowConsumer(name -> System.out.println(Class.forName(name)))); or .forEach(rethrowConsumer(ClassNameUtil::println)); */
public static <T, E extends Exception> Consumer<T> rethrowConsumer(Consumer_WithExceptions<T, E> consumer) throws E {
    return t -> {
        try { consumer.accept(t); }
        catch (Exception exception) { throwAsUnchecked(exception); }
        };
    }

public static <T, U, E extends Exception> BiConsumer<T, U> rethrowBiConsumer(BiConsumer_WithExceptions<T, U, E> biConsumer) throws E {
    return (t, u) -> {
        try { biConsumer.accept(t, u); }
        catch (Exception exception) { throwAsUnchecked(exception); }
        };
    }

/** .map(rethrowFunction(name -> Class.forName(name))) or .map(rethrowFunction(Class::forName)) */
public static <T, R, E extends Exception> Function<T, R> rethrowFunction(Function_WithExceptions<T, R, E> function) throws E {
    return t -> {
        try { return function.apply(t); }
        catch (Exception exception) { throwAsUnchecked(exception); return null; }
        };
    }

/** rethrowSupplier(() -> new StringJoiner(new String(new byte[]{77, 97, 114, 107}, "UTF-8"))), */
public static <T, E extends Exception> Supplier<T> rethrowSupplier(Supplier_WithExceptions<T, E> function) throws E {
    return () -> {
        try { return function.get(); }
        catch (Exception exception) { throwAsUnchecked(exception); return null; }
        };
    }

/** uncheck(() -> Class.forName("xxx")); */
public static void uncheck(Runnable_WithExceptions t)
    {
    try { t.run(); }
    catch (Exception exception) { throwAsUnchecked(exception); }
    }

/** uncheck(() -> Class.forName("xxx")); */
public static <R, E extends Exception> R uncheck(Supplier_WithExceptions<R, E> supplier)
    {
    try { return supplier.get(); }
    catch (Exception exception) { throwAsUnchecked(exception); return null; }
    }

/** uncheck(Class::forName, "xxx"); */
public static <T, R, E extends Exception> R uncheck(Function_WithExceptions<T, R, E> function, T t) {
    try { return function.apply(t); }
    catch (Exception exception) { throwAsUnchecked(exception); return null; }
    }

@SuppressWarnings ("unchecked")
private static <E extends Throwable> void throwAsUnchecked(Exception exception) throws E { throw (E)exception; }

}

许多其他关于如何使用它的例子(在静态导入LambdaExceptionUtil之后):

@Test
public void test_Consumer_with_checked_exceptions() throws IllegalAccessException {
    Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String")
          .forEach(rethrowConsumer(className -> System.out.println(Class.forName(className))));

    Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String")
          .forEach(rethrowConsumer(System.out::println));
    }

@Test
public void test_Function_with_checked_exceptions() throws ClassNotFoundException {
    List<Class> classes1
          = Stream.of("Object", "Integer", "String")
                  .map(rethrowFunction(className -> Class.forName("java.lang." + className)))
                  .collect(Collectors.toList());

    List<Class> classes2
          = Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String")
                  .map(rethrowFunction(Class::forName))
                  .collect(Collectors.toList());
    }

@Test
public void test_Supplier_with_checked_exceptions() throws ClassNotFoundException {
    Collector.of(
          rethrowSupplier(() -> new StringJoiner(new String(new byte[]{77, 97, 114, 107}, "UTF-8"))),
          StringJoiner::add, StringJoiner::merge, StringJoiner::toString);
    }

@Test    
public void test_uncheck_exception_thrown_by_method() {
    Class clazz1 = uncheck(() -> Class.forName("java.lang.String"));

    Class clazz2 = uncheck(Class::forName, "java.lang.String");
    }

@Test (expected = ClassNotFoundException.class)
public void test_if_correct_exception_is_still_thrown_by_method() {
    Class clazz3 = uncheck(Class::forName, "INVALID");
    }    

截至2015年11月，代码在@PaoloC的帮助下得到了改进，请检查下面他的回答并投票。他帮助解决了最后一个问题:现在编译器会要求您添加抛出子句，一切就好像您可以在Java 8流上本机抛出检查异常一样。

注1:上面LambdaExceptionUtil类的重抛出方法可以毫无顾虑地使用，并且可以在任何情况下使用。

注2:上面LambdaExceptionUtil类的取消检查方法是额外的方法，如果你不想使用它们，可以安全地从类中删除它们。如果你确实使用了它们，请谨慎使用，在了解以下用例、优点/缺点和限制之前不要使用:

•如果你调用的方法永远不会抛出它声明的异常，你可以使用uncheck方法。例如:new String(byteArr， "UTF-8")抛出UnsupportedEncodingException，但Java规范保证UTF-8始终存在。在这里，throws声明是一个麻烦，任何用最小样板文件来沉默它的解决方案都是受欢迎的:String text = uncheck(() -> new String(byteArr， "UTF-8"));

•如果你正在实现一个严格的接口，你没有添加throws声明的选项，但抛出一个异常是完全合适的，你可以使用uncheck方法。包装一个异常只是为了获得抛出它的特权，结果是一个带有虚假异常的堆栈跟踪，这些异常没有提供关于实际错误的信息。一个很好的例子是Runnable.run()，它不会抛出任何受控异常。

• In any case, if you decide to use the uncheck methods, be aware of these 2 consequences of throwing CHECKED exceptions without a throws clause: 1) The calling-code won't be able to catch it by name (if you try, the compiler will say: Exception is never thrown in body of corresponding try statement). It will bubble and probably be caught in the main program loop by some "catch Exception" or "catch Throwable", which may be what you want anyway. 2) It violates the principle of least surprise: it will no longer be enough to catch RuntimeException to be able to guarantee catching all possible exceptions. For this reason, I believe this should not be done in framework code, but only in business code that you completely control.

引用:

http://www.philandstuff.com/2012/04/28/sneakily-throwing-checked-exceptions.html http://www.mail-archive.com/javaposse@googlegroups.com/msg05984.html Project Lombok注释:@SneakyThrows Brian Goetz的观点(反对):我如何在Java 8流中抛出CHECKED异常? https://softwareengineering.stackexchange.com/questions/225931/workaround-for-java-checked-exceptions?newreg=ddf0dd15e8174af8ba52e091cf85688e *

我使用这种包装异常:

public class CheckedExceptionWrapper extends RuntimeException {
    ...
    public <T extends Exception> CheckedExceptionWrapper rethrow() throws T {
        throw (T) getCause();
    }
}

它需要静态处理这些异常:

void method() throws IOException, ServletException {
    try { 
        list.stream().forEach(object -> {
            ...
            throw new CheckedExceptionWrapper(e);
            ...            
        });
    } catch (CheckedExceptionWrapper e){
        e.<IOException>rethrow();
        e.<ServletExcepion>rethrow();
    }
}

在网上试试!

尽管在第一次rethrow()调用期间无论如何都会重新抛出异常(哦，Java泛型…)，这种方式允许获得可能异常的严格静态定义(需要在抛出中声明它们)。不需要instanceof或其他东西。

这样做是不安全的。你可以作弊，但你的程序坏了，这将不可避免地反过来伤害别人(应该是你，但我们的作弊经常会伤害到别人)。

这里有一个稍微安全一点的方法(但我仍然不推荐这样做)。

class WrappedException extends RuntimeException {
    Throwable cause;

    WrappedException(Throwable cause) { this.cause = cause; }
}

static WrappedException throwWrapped(Throwable t) {
    throw new WrappedException(t);
}

try 
    source.stream()
          .filter(e -> { ... try { ... } catch (IOException e) { throwWrapped(e); } ... })
          ...
}
catch (WrappedException w) {
    throw (IOException) w.cause;
}

在这里，您要做的是捕获lambda中的异常，从流管道中抛出一个信号，表明计算异常失败，捕获信号，并对该信号进行操作以抛出底层异常。关键是您总是捕获合成异常，而不是在没有声明抛出异常的情况下允许已检查异常泄漏。

我写了一个扩展Stream API的库，以允许抛出受控异常。它使用了Brian Goetz的技巧。

您的代码将变成

public List<Class> getClasses() throws ClassNotFoundException {     
    Stream<String> classNames = 
        Stream.of("java.lang.Object", "java.lang.Integer", "java.lang.String");

    return ThrowingStream.of(classNames, ClassNotFoundException.class)
               .map(Class::forName)
               .collect(Collectors.toList());
}

这个答案类似于17，但避免了包装器异常定义:

List test = new ArrayList();
        try {
            test.forEach(obj -> {

                //let say some functionality throws an exception
                try {
                    throw new IOException("test");
                }
                catch(Exception e) {
                    throw new RuntimeException(e);
                }
            });
        }
        catch (RuntimeException re) {
            if(re.getCause() instanceof IOException) {
                //do your logic for catching checked
            }
            else 
                throw re; // it might be that there is real runtime exception
        }