Use setRoundingMode
, set the RoundingMode
explicitly to handle your issue with the half-even round, then use the format pattern for your required output.
Example:
DecimalFormat df = new DecimalFormat("#.####");
df.setRoundingMode(RoundingMode.CEILING);
for (Number n : Arrays.asList(12, 123.12345, 0.23, 0.1, 2341234.212431324)) {
Double d = n.doubleValue();
System.out.println(df.format(d));
}
gives the output:
12
123.1235
0.23
0.1
2341234.2125
EDIT: The original answer does not address the accuracy of the double values. That is fine if you don't care much whether it rounds up or down. But if you want accurate rounding, then you need to take the expected accuracy of the values into account. Floating point values have a binary representation internally. That means that a value like 2.7735 does not actually have that exact value internally. It can be slightly larger or slightly smaller. If the internal value is slightly smaller, then it will not round up to 2.7740. To remedy that situation, you need to be aware of the accuracy of the values that you are working with, and add or subtract that value before rounding. For example, when you know that your values are accurate up to 6 digits, then to round half-way values up, add that accuracy to the value:
Double d = n.doubleValue() + 1e-6;
To round down, subtract the accuracy.
Using Java 6 or later, the classpath option supports wildcards. Note the following:
- Use straight quotes (
"
)
- Use
*
, not *.jar
Windows
java -cp "Test.jar;lib/*" my.package.MainClass
Unix
java -cp "Test.jar:lib/*" my.package.MainClass
This is similar to Windows, but uses :
instead of ;
. If you cannot use wildcards, bash
allows the following syntax (where lib
is the directory containing all the Java archive files):
java -cp "$(printf %s: lib/*.jar)"
(Note that using a classpath is incompatible with the -jar
option. See also: Execute jar file with multiple classpath libraries from command prompt)
Understanding Wildcards
From the Classpath document:
Class path entries can contain the basename wildcard character *
, which is considered equivalent to specifying a list of all the files
in the directory with the extension .jar
or .JAR
. For example, the
class path entry foo/*
specifies all JAR files in the directory named
foo. A classpath entry consisting simply of *
expands to a list of all
the jar files in the current directory.
A class path entry that contains *
will not match class files. To
match both classes and JAR files in a single directory foo, use either
foo;foo/*
or foo/*;foo
. The order chosen determines whether the
classes and resources in foo
are loaded before JAR files in foo
, or
vice versa.
Subdirectories are not searched recursively. For example, foo/*
looks
for JAR files only in foo
, not in foo/bar
, foo/baz
, etc.
The order in which the JAR files in a directory are enumerated in the
expanded class path is not specified and may vary from platform to
platform and even from moment to moment on the same machine. A
well-constructed application should not depend upon any particular
order. If a specific order is required then the JAR files can be
enumerated explicitly in the class path.
Expansion of wildcards is done early, prior to the invocation of a
program's main method, rather than late, during the class-loading
process itself. Each element of the input class path containing a
wildcard is replaced by the (possibly empty) sequence of elements
generated by enumerating the JAR files in the named directory. For
example, if the directory foo
contains a.jar
, b.jar
, and c.jar
, then
the class path foo/*
is expanded into foo/a.jar;foo/b.jar;foo/c.jar
,
and that string would be the value of the system property
java.class.path
.
The CLASSPATH
environment variable is not treated any differently from
the -classpath
(or -cp
) command-line option. That is, wildcards are
honored in all these cases. However, class path wildcards are not
honored in the Class-Path jar-manifest
header.
Note: due to a known bug in java 8, the windows examples must use a backslash preceding entries with a trailing asterisk: https://bugs.openjdk.java.net/browse/JDK-8131329
Best Answer
Here is what I personally add to my ant files (build.xml) :
With Netbeans call these targets manually, or you can use hook targets :