小编VMN*_*VMN的帖子

BigDecimal.add当一个参数具有大指数(9位数)时,方法需要很长时间,而第二个参数具有不同长度的指数.我已经等了5分钟以上,而且还在继续.

这是代码:

@Test
public void testAddBig() throws Exception {
    MathContext mc = new MathContext(10, RoundingMode.HALF_UP);
    BigDecimal v1 = new BigDecimal("1E+100000000", mc);
    BigDecimal v2 = new BigDecimal("1", mc);
    System.out.println(v1.add(v2));
}

这是线程转储的一部分:

at java.math.BigInteger.square(BigInteger.java:1884)
at java.math.BigInteger.squareKaratsuba(BigInteger.java:1975)
at java.math.BigInteger.square(BigInteger.java:1888)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2011)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2006)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2012)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2010)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2006)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2012)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.squareToomCook3(BigInteger.java:2011)
at java.math.BigInteger.square(BigInteger.java:1890)
at java.math.BigInteger.pow(BigInteger.java:2263)
at java.math.BigDecimal.bigTenToThe(BigDecimal.java:3543)
at java.math.BigDecimal.bigMultiplyPowerTen(BigDecimal.java:4508)
at java.math.BigDecimal.add(BigDecimal.java:4443)
at java.math.BigDecimal.add(BigDecimal.java:1289)

到底是怎么回事？这是一个错误吗？

ValueListBox没有实现HasEnabled接口,所以我无法禁用/启用它.

虽然ListBox实现了HasEnabled,但是方法getListBox在ValueListBox中是私有的.所以我无法得到内部列表框,禁用它.

谁知道如何解决这个问题？提前致谢.