Question

我想利用此site给出的工具，该工具本质上能够采用简单的POJO类，并输出生成的junit测试。但是，该代码使用Java 8（需要在Java 7中）。与以下代码段等效的Java 7是什么？主要是需要转换的lambda表达式。

代码：

公共抽象类DtoTest {

/** A map of default mappers for common objects. */
private static final ImmutableMap<Class<?>, Supplier<t>> DEFAULT_MAPPERS;

static {
    final Builder<Class<?>, Supplier<?>> mapperBuilder = ImmutableMap.builder();

    /* Primitives */
    mapperBuilder.put(int.class, () -> 0);
    mapperBuilder.put(double.class, () -> 0.0d);
    mapperBuilder.put(float.class, () -> 0.0f);
    mapperBuilder.put(long.class, () -> 0l);
    mapperBuilder.put(boolean.class, () -> true);
    mapperBuilder.put(short.class, () -> (short) 0);
    mapperBuilder.put(byte.class, () -> (byte) 0);
    mapperBuilder.put(char.class, () -> (char) 0);

    mapperBuilder.put(Integer.class, () -> Integer.valueOf(0));
    mapperBuilder.put(Double.class, () -> Double.valueOf(0.0));
    mapperBuilder.put(Float.class, () -> Float.valueOf(0.0f));
    mapperBuilder.put(Long.class, () -> Long.valueOf(0));
    mapperBuilder.put(Boolean.class, () -> Boolean.TRUE);
    mapperBuilder.put(Short.class, () -> Short.valueOf((short) 0));
    mapperBuilder.put(Byte.class, () -> Byte.valueOf((byte) 0));
    mapperBuilder.put(Character.class, () -> Character.valueOf((char) 0));

    mapperBuilder.put(BigDecimal.class, () -> BigDecimal.ONE);
    mapperBuilder.put(Date.class, () -> new Date());

    /* Collection Types. */
    mapperBuilder.put(Set.class, () -> Collections.emptySet());
    mapperBuilder.put(SortedSet.class, () -> Collections.emptySortedSet());
    mapperBuilder.put(List.class, () -> Collections.emptyList());
    mapperBuilder.put(Map.class, () -> Collections.emptyMap());
    mapperBuilder.put(SortedMap.class, () -> Collections.emptySortedMap());

    DEFAULT_MAPPERS = mapperBuilder.build();
}

Answer 1

如果使用的是IntelliJ，则可以使用扩展表达式。 Alt + Enter->展开lambda

将Lambda表达式转换为JAVA 7

1 个答案: