blocks|key|1259038|text|请注意，转换为long和转换为Long之间存在差异。如果您强制转换为long+(原始值)，那么它应该自动装箱为Long+(包装它的引用类型)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1259039|您也可以使用new创建一个Long实例，并使用int值对其进行初始化。|1259040|entityMap^0|7|4|F|4|Y|4|1J|4|0|6|3|D|4|N|3|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|I|$]]

Note that there is a difference between a cast to <code>long</code> and a cast to <code>Long</code>. If you cast to <code>long</code> (a primitive value) then it should be automatically boxed to a <code>Long</code> (the reference type that wraps it).

You could alternatively use <code>new</code> to create an instance of <code>Long</code>, initializing it with the <code>int</code> value.

blocks|key|1473748|text|使用以下命令：Long.valueOf(int);。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1473749|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/Long.html#valueOf%2528long%2529^0|7|I|7|I|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

Use the following: <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Long.html#valueOf%28long%29" rel="noreferrer"><code>Long.valueOf(int);</code></a>.

blocks|key|1473765|text|如果已经将int类型化为Integer，则可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1473766|Integer+y+=+1;
long+x+=+y.longValue();|code-block|syntax|javascript|1473767|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you already have the int typed as an Integer you can do this:

<pre><code>Integer y = 1;
long x = y.longValue();
</code></pre>

blocks|key|1259297|text|使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1259298|new+Long(your_integer);|code-block|syntax|javascript|1259299|或|1259300|Long.valueOf(your_integer);|1259301|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

use 

<pre><code>new Long(your_integer);
</code></pre>

or

<pre><code>Long.valueOf(your_integer);
</code></pre>

blocks|key|1474068|text|+1,new+Long(intValue);
+2,Long.valueOf(intValue);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1474069|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> 1,new Long(intValue);
 2,Long.valueOf(intValue);
</code></pre>

blocks|key|1473861|text|我有一个小玩具，它也可以处理非泛型接口。如果输入错误，我可以抛出一个ClassCastException+(好的，快乐的)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1473862|public+class+TypeUtil+{
++++public+static+long+castToLong(Object+o)+{
++++++++Number+n+=+(Number)+o;
++++++++return+n.longValue();
++++}
}|code-block|syntax|javascript|1473863|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I have this little toy, that also deals with non generic interfaces.
I'm OK with it throwing a ClassCastException if feed wrong (OK and happy)

<pre><code>public class TypeUtil {
 public static long castToLong(Object o) {
 Number n = (Number) o;
 return n.longValue();
 }
}
</code></pre>

blocks|key|1473895|text|在Java中，您可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1473896|+int+myInt=4;
+Long+myLong=+new+Long(myInt);|code-block|syntax|javascript|1473897|在您的情况下，它将是：|1473898|content.setSequence(new+Long(i));|1473899|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

In Java you can do:

<pre><code> int myInt=4;
 Long myLong= new Long(myInt);
</code></pre>

in your case it would be: 

<pre><code>content.setSequence(new Long(i));
</code></pre>

blocks|key|1473961|text|我们将通过使用Number引用来获得长整型值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1473962|public+static+long+toLong(Number+number){
++++return+number.longValue();
}|code-block|syntax|javascript|1473963|它适用于所有数字类型，下面是一个测试：|1473964|public+static+void+testToLong()+throws+Exception+{
++++assertEquals(0l,+toLong(0));+++//+an+int
++++assertEquals(0l,+toLong((short)0));+//+a+short
++++assertEquals(0l,+toLong(0l));+//+a+long
++++assertEquals(0l,+toLong((long)+0));+//+another+long
++++assertEquals(0l,+toLong(0.0f));++//+a+float
++++assertEquals(0l,+toLong(0.0));++//+a+double

}|1473965|entityMap^0|7|6|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

We shall get the long value by using <code>Number</code> reference.

<pre><code>public static long toLong(Number number){
 return number.longValue();
}
</code></pre>

It works for all number types, here is a test:

<pre><code>public static void testToLong() throws Exception {
 assertEquals(0l, toLong(0)); // an int
 assertEquals(0l, toLong((short)0)); // a short
 assertEquals(0l, toLong(0l)); // a long
 assertEquals(0l, toLong((long) 0)); // another long
 assertEquals(0l, toLong(0.0f)); // a float
 assertEquals(0l, toLong(0.0)); // a double

}
</code></pre>

blocks|key|1259093|text|我在这方面遇到了很多麻烦。我只想说：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1259094|thisBill.IntervalCount+=+jPaidCountSpinner.getValue();|code-block|syntax|javascript|1259095|其中IntervalCount是一个长整型，而JSpinner被设置为返回一个长整型。最终我不得不写这个函数：|1259096|++++public+static+final+Long+getLong(Object+obj)+throws+IllegalArgumentException+{
++++Long+rv;

++++if((obj.getClass()+==+Integer.class)+%7C%7C+(obj.getClass()+==+Long.class)+%7C%7C+(obj.getClass()+==+Double.class))+{
++++++++rv+=+Long.parseLong(obj.toString());
++++}
++++else+if((obj.getClass()+==+int.class)+%7C%7C+(obj.getClass()+==+long.class)+%7C%7C+(obj.getClass()+==+double.class))+{
++++++++rv+=+(Long)+obj;
++++}
++++else+if(obj.getClass()+==+String.class)+{
++++++++rv+=+Long.parseLong(obj.toString());
++++}
++++else+{
++++++++throw+new+IllegalArgumentException("getLong:+type+"+%2B+obj.getClass()+%2B+"+=+\""+%2B+obj.toString()+%2B+"\"+unaccounted+for");
++++}

++++return+rv;
}|1259097|这看起来很管用。无论多简单的铸造，上面的解决方案对我来说都不起作用。非常令人沮丧。|1259098|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I had a great deal of trouble with this. I just wanted to:

<pre><code>thisBill.IntervalCount = jPaidCountSpinner.getValue();
</code></pre>

Where IntervalCount is a Long, and the JSpinner was set to return a Long. Eventually I had to write this function:

<pre><code> public static final Long getLong(Object obj) throws IllegalArgumentException {
 Long rv;

 if((obj.getClass() == Integer.class) || (obj.getClass() == Long.class) || (obj.getClass() == Double.class)) {
 rv = Long.parseLong(obj.toString());
 }
 else if((obj.getClass() == int.class) || (obj.getClass() == long.class) || (obj.getClass() == double.class)) {
 rv = (Long) obj;
 }
 else if(obj.getClass() == String.class) {
 rv = Long.parseLong(obj.toString());
 }
 else {
 throw new IllegalArgumentException("getLong: type " + obj.getClass() + " = \"" + obj.toString() + "\" unaccounted for");
 }

 return rv;
}
</code></pre>

which seems to do the trick. No amount of simple casting, none of the above solutions worked for me. Very frustrating.

blocks|key|1259319|text|+//Suppose+you+have+int+and+you+wan+to+convert+it+to+Long
+int+i=78;
+//convert+to+Long
+Long+l=Long.valueOf(i)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1259320|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> //Suppose you have int and you wan to convert it to Long
 int i=78;
 //convert to Long
 Long l=Long.valueOf(i)
</code></pre>

blocks|key|1259407|text|建议从Android+Studio+lint检查:删除不必要的装箱:所以，取消装箱是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1259408|public++static++long++integerToLong+(int+minute+){
++++int+delay+=+minute*1000;
++++long+diff+=+(long)+delay;
++++return++diff+;+
}|code-block|syntax|javascript|1259409|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Suggested From Android Studio lint check : Remove Unnecessary boxing : So, unboxing is :
<pre><code>public static long integerToLong (int minute ){
 int delay = minute*1000;
 long diff = (long) delay;
 return diff ; 
}
</code></pre>

blocks|key|1474054|text|一旦只有一个方法Long.valueOf(long)，在使用Long.valueOf(intValue)的情况下，将隐式地完成从int到long的转换。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1474055|更清晰的方法是|1474056|Integer.valueOf(intValue).longValue()|code-block|syntax|javascript|1474057|entityMap^0|8|I|U|M|1S|3|1W|4|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|N|$]]

As soon as there is only method <code>Long.valueOf(long)</code>, cast from <code>int</code> to <code>long</code> will be done implicitly in case of using <code>Long.valueOf(intValue)</code>.

The more clear way to do this is

<pre><code>Integer.valueOf(intValue).longValue()
</code></pre>

blocks|key|1259440|text|除了这里建议的其他方法外，还可以尝试下面的代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1259441|(long)intValue|code-block|syntax|javascript|1259442|原始到原始。|1259443|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Apart from the other ways suggested here, one can try the below code as well.
<pre><code>(long)intValue
</code></pre>
primitive to primitive.

I keep finding both on here and Google people having troubles going from <code>long</code> to <code>int</code> and not the other way around. Yet I'm sure I'm not the only one that has run into this scenario before going from <code>int</code> to <code>Long</code>.

The only other answers I've found were "Just set it as Long in the first place" which really doesn't address the question.

I initially tried casting but I get a "<code>Cannot cast from int to Long</code>"

<pre><code>for (int i = 0; i &lt; myArrayList.size(); ++i ) {
 content = new Content();
 content.setDescription(myArrayList.get(i));
 content.setSequence((Long) i);
 session.save(content);
}
</code></pre>

As you can imagine I'm a little perplexed, I'm stuck using <code>int</code> since some content is coming in as an <code>ArrayList</code> and the entity for which I'm storing this info requires the sequence number as a Long.

How do I convert from int to Long in Java?

Android Studio

Android

Java

我在这里和谷歌上不断地发现，人们在从long到int的过程中遇到了麻烦，而不是反过来。然而，我确信我不是唯一一个在从int到Long之前遇到这种情况的人。我找到的唯一其他答案是“一开始就把它设置得尽可能长”，这真的没有解决这个问题。我最初试了试，但得到了一个"Cannot cast from int to Long“for (int i = 0; i < myArrayList.size(); +

问如何在Java中将int转换为Long？
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