Di Jawa bagaimana cara bergabung dengan Array? 3 cara: Apache Commons ArrayUtils, Java 8 Streams, dan API Sederhana
Diterbitkan: 2022-01-20
Dalam tutorial ini kita akan membahas berbagai cara untuk bergabung dengan Java Array.
Jika Anda memiliki pertanyaan di bawah ini maka Anda berada di tempat yang tepat:
- Bagaimana saya bisa menggabungkan dua array di Jawa?
- Bagaimana Menggabungkan Dua Array di Jawa?
- 3 Cara Menggabungkan Array di Java
- Bergabunglah dengan Array Primitif dengan Separator di Java
Berikut adalah tiga cara Anda bisa bergabung dengan array di Jawa.
- Bergabunglah dengan Array menggunakan utilitas Apache Common
- Bergabunglah dengan Array menggunakan operasi Java8 Stream
- Bergabunglah dengan Array menggunakan API Java Standar
Mari kita mulai:
Buat kelas Java CrunchifyJoinArrays3Ways.java
.
Masukkan kode Java di bawah ini ke dalam file.
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package crunchify . com . tutorial ; import org . apache . commons . lang3 . ArrayUtils ; import java . lang . reflect . Array ; import java . util . Arrays ; import java . util . stream . IntStream ; import java . util . stream . Stream ; /** * @author Crunchify.com * <p> * In Java how to join Arrays? 3 ways: Apache Commons ArrayUtils, Java 8 Streams and Simple APIs. * Version: 1.0.3 */ public class CrunchifyJoinArrays3Ways { public static void main ( String [ ] args ) { crunchifyPrint ( "Original String Array1: [google, twitter]" ) ; crunchifyPrint ( "Original String Array2: [apple, microsoft]" ) ; crunchifyPrint ( "Original Integer Array1: [111, 444]" ) ; crunchifyPrint ( "Original Integer Array2: [222, 555]\n" ) ; // Join Array using Apache Common utility joinArrayUsingApacheCommon ( ) ; // Join Array using Java8 Stream operation joinArrayUsingJava8Stream ( ) ; // Join Array using Standard Java APIs joinArrayUsingJavaAPI ( ) ; } // Method-1: Join Array using Apache Common utility private static void joinArrayUsingApacheCommon ( ) { String [ ] company1 = new String [ ] { "google" , "twitter" } ; String [ ] company2 = new String [ ] { "apple" , "microsoft" } ; // from org.apache.commons.lang3 maven dependency String [ ] crunchifyResult = ArrayUtils . addAll ( company1 , company2 ) ; crunchifyPrint ( "From Method-1: addAll() - String ==> " + Arrays . toString ( crunchifyResult ) ) ; int [ ] crunchifyArray1 = new int [ ] { 111 , 444 } ; int [ ] crunchifyArray2 = new int [ ] { 222 , 555 } ; int [ ] crunchifyResult2 = ArrayUtils . addAll ( crunchifyArray1 , crunchifyArray2 ) ; crunchifyPrint ( "From Method-1: addAll() - Integer ==> " + Arrays . toString ( crunchifyResult2 ) ) ; } // Simple Java Print Method private static void crunchifyPrint ( String result ) { System . out . println ( result ) ; } // Method-2: Join Array using Java8 Stream operation private static void joinArrayUsingJava8Stream ( ) { String [ ] company1 = new String [ ] { "google" , "twitter" } ; String [ ] company2 = new String [ ] { "apple" , "microsoft" } ; // Stream.of() - returns a sequential ordered stream whose elements are the specified values. // A sequence of elements supporting sequential and parallel aggregate operations. The following example illustrates an aggregate operation using Stream and IntStream: // // int sum = widgets.stream() // .filter(w -> w.getColor() == RED) // .mapToInt(w -> w.getWeight()) // .sum(); String [ ] result = Stream . of ( company1 , company2 ) . flatMap ( Stream : : of ) . toArray ( String [ ] : : new ) ; crunchifyPrint ( "\nFrom Method-2: Stream.of() ==> " + Arrays . toString ( result ) ) ; int [ ] crunchifyArray1 = new int [ ] { 111 , 444 } ; int [ ] crunchifyArray2 = new int [ ] { 222 , 555 } ; // Arrays.stream() - returns a sequential IntStream with the specified array as its source. int [ ] crunchifyResult2 = IntStream . concat ( Arrays . stream ( crunchifyArray1 ) , Arrays . stream ( crunchifyArray2 ) ) . toArray ( ) ; crunchifyPrint ( "From Method-2: IntStream.concat() ==> " + Arrays . toString ( crunchifyResult2 ) ) ; } // Method-3: Join Array using Standard Java APIs private static void joinArrayUsingJavaAPI ( ) { String [ ] company1 = new String [ ] { "google" , "twitter" } ; String [ ] company2 = new String [ ] { "apple" , "microsoft" } ; String [ ] crunchifyResult = crunchifyJoinGenericArray ( company1 , company2 ) ; crunchifyPrint ( "\nFrom Method-3: crunchifyJoinArrayusingGeneric() ==> " + Arrays . toString ( crunchifyResult ) ) ; int [ ] crunchifyArray1 = new int [ ] { 111 , 444 } ; int [ ] crunchifyArray2 = new int [ ] { 222 , 555 } ; int [ ] crunchifyResult2 = crunchifyJoinIntegerArray ( crunchifyArray1 , crunchifyArray2 ) ; // Arrays.toString() Returns a string representation of the contents of the specified array. // The string representation consists of a list of the array's elements, enclosed in square brackets ("[]"). // Adjacent elements are separated by the characters ", " (a comma followed by a space). // Elements are converted to strings as by String.valueOf(int). Returns "null" if a is null. crunchifyPrint ( "From Method-3: joinArray() ==> " + Arrays . toString ( crunchifyResult2 ) ) ; } @ SafeVarargs private static < T > T [ ] crunchifyJoinGenericArray ( T [ ] . . . crunchifyArrays ) { int crunchify = 0 ; for ( T [ ] crunchifyArray : crunchifyArrays ) { crunchify += crunchifyArray . length ; } //T[] result = new T[crunchify]; final T [ ] crunchifyResult = ( T [ ] ) Array . newInstance ( crunchifyArrays [ 0 ] . getClass ( ) . getComponentType ( ) , crunchify ) ; int crunchifyOffset = 0 ; for ( T [ ] crunchifyArray : crunchifyArrays ) { // Copies an array from the specified source array, beginning at the specified position, to the specified position of the destination array. // A subsequence of array components are copied from the source array referenced by src to the destination array referenced by dest. // The number of components copied is equal to the length argument. // The components at positions srcPos through srcPos+length-1 in the source array are copied into positions destPos through destPos+length-1, respectively, of the destination array. System . arraycopy ( crunchifyArray , 0 , crunchifyResult , crunchifyOffset , crunchifyArray . length ) ; crunchifyOffset += crunchifyArray . length ; } return crunchifyResult ; } private static int [ ] crunchifyJoinIntegerArray ( int [ ] . . . crunchifyArrays ) { int crunchify = 0 ; for ( int [ ] crunchifyArray : crunchifyArrays ) { crunchify += crunchifyArray . length ; } final int [ ] crunchifyResult = new int [ crunchify ] ; int crunchifyOffset = 0 ; for ( int [ ] crunchifyArray : crunchifyArrays ) { System . arraycopy ( crunchifyArray , 0 , crunchifyResult , crunchifyOffset , crunchifyArray . length ) ; crunchifyOffset += crunchifyArray . length ; } return crunchifyResult ; } } |
Mari kita lihat beberapa detail Java API.

java.lang.System.arraycopy():

java.util.Arrays.toString():

java.util.stream():


Jalankan program sebagai Program Java dan Anda akan melihat hasil yang sama seperti di bawah ini.
Keluaran konsol IntelliJ IDEA:
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/ Library / Java / JavaVirtualMachines / jdk - 15.jdk / Contents / Home / bin / java - javaagent : / Applications / IntelliJ IDEA . app / Contents / lib / idea_rt . jar = 50249 : / Applications / IntelliJ IDEA . app / Contents / bin - Dfile . encoding = UTF - 8 - classpath / Users / app / crunchify / github / CrunchifyTutorials / target / classes : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / zxing - 2.1.jar / Users / app / . m2 / repository / commons - collections / commons - collections / 3.2.1 / commons - collections - 3.2.1.jar / spring - context - support - 5.1.3.RELEASE.jar crunchify . com . tutorial . CrunchifyJoinArrays3Ways Original String Array1 : [ google , twitter ] Original String Array2 : [ apple , microsoft ] Original Integer Array1 : [ 111 , 444 ] Original Integer Array2 : [ 222 , 555 ] From Method - 1 : addAll ( ) - String == > [ google , twitter , apple , microsoft ] From Method - 1 : addAll ( ) - Integer == > [ 111 , 444 , 222 , 555 ] From Method - 2 : Stream . of ( ) == > [ google , twitter , apple , microsoft ] From Method - 2 : IntStream . concat ( ) == > [ 111 , 444 , 222 , 555 ] From Method - 3 : crunchifyJoinArrayusingGeneric ( ) == > [ google , twitter , apple , microsoft ] From Method - 3 : joinArray ( ) == > [ 111 , 444 , 222 , 555 ] Process finished with exit code 0 |
Tolong beri tahu saya jika Anda memiliki cara lain untuk menggabungkan Java Array atau Anda mendapatkan pengecualian.