我正在尝试在java中实现一个简单的方法，要求如下：
使用分隔符将字符串拆分为列表。如果在分隔符之前放置“\”，则该字符被视为普通字符。例如，如果“;” 用作分隔符，字符串“a;b;cc;\;;;” 将被转换成一个字符串列表：[“a”, “b”, “cc”, “;”, null, null]
我已经编写了所有代码和单元测试，但我不确定是否缺少某些案例。请给我一些改进代码的建议，无论是关于性能或维护（干净的代码）。我也会尝试重构代码。
请给点意见，谢谢。
我只是在学习，不是为了项目。我如何证明实施是正确的？
import java.util.ArrayList;
import java.util.List;
public class SplitStringUtil {
public static List<String> splitStringIntoList(String str, String delimiter) {
char TRANSLATOR_CHAR = '\\';
List<String> list = new ArrayList<String>();
char[] charArr = str.toCharArray();
char[] delimiterArr = delimiter.toCharArray();
int i = 0;
int pos = 0;
while (i < charArr.length) {
char temp = charArr[i];
if (temp == delimiterArr[0]) {
boolean isDelimiter = true;
if (delimiterArr.length > 1) {// delimiter's length larger than
// 1
for (int j = 1; j < delimiterArr.length; j++) {
if (delimiterArr[j] != charArr[i + j]) {
isDelimiter = false;
i += j;
break;
}
}
} else if (i > 0 && charArr[i - 1] == TRANSLATOR_CHAR) {
isDelimiter = false;
i++;
continue;
}
if (isDelimiter) {
char[] tempArr = new char[i - pos];
System.arraycopy(charArr, pos, tempArr, 0, i - pos);
tempArr = removeSlashFromCharArr(tempArr, 0, tempArr.length);
list.add(String.valueOf(tempArr));
pos = i + delimiter.length();
i += delimiter.length();
if (i == charArr.length) {
list.add("");
}
}
} else {
i++;
if (i == charArr.length) {
char[] tempArr = new char[i - pos];
System.arraycopy(charArr, pos, tempArr, 0, i - pos);
tempArr = removeSlashFromCharArr(tempArr, 0, tempArr.length);
list.add(String.valueOf(tempArr));
pos = i + delimiter.length();
i += delimiter.length();
}
}
}
return list;
}
public static char[] removeSlashFromCharArr(char[] arr, int start, int end) {
char[] tempArr = arr.clone();
int count = 0;
for (int i = start; i < end; i++) {
if (tempArr[i] == '\\') {
count++;
for (int j = i; j < end - 1; j++) {
tempArr[j] = tempArr[j + 1];
}
}
}
char[] resArr = new char[tempArr.length - count];
System.arraycopy(tempArr, 0, resArr, 0, resArr.length);
return resArr;
}
}
import static org.junit.Assert.assertEquals;
import java.util.List;
import org.junit.Test;
public class SplitStringUtilTest {
@Test
public void testStringValueOfWithZeroAndZero() {
char[] arr = { 'a', 'b', 'c' };
assertEquals(String.valueOf(arr, 0, 0), "");// String.valueOf(charArr,
// 0, 0) return "" instead
// of null
assertEquals(String.valueOf(arr, 0, 1), "a");
// assertNull(String.valueOf(arr, 0, 0));// fail
}
@Test
public void testNewStringWithNotAssignedCharInside(){
char[] arr = new char[4];
arr[0] = 'a';
arr[2] = 'b';
char notAssignedChar = '\u0000';
String s = String.valueOf(arr);
assertEquals(s,"a\u0000b\u0000");
}
@Test
public void testNormal() {
String str = "a;b;c";
List<String> list = SplitStringUtil.splitStringIntoList(str, ";");
String[] arr = str.split(";");
assertEquals(arr.length, list.size());
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testDelimiterHasMoreThanOneChar() {
String str = "abcd";
List<String> list = SplitStringUtil.splitStringIntoList(str, "bc");
String[] arr = str.split("bc");
assertEquals(arr.length, list.size());
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testWithNoDelimiterExist(){
String str = "abc";
String delimiter = ";";
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
assertEquals(list.get(0),str);
}
@Test
public void testStartWithDelimiter(){
String str = ";a;b;c;d";
String delimiter = ";";
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
String[] arr = str.split(delimiter);
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testEndWithDelimiter(){
String str = ";a;b;c;d;";
String delimiter = ";";
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
String[] arr = {"","a","b","c","d",""};
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testStartWithSlash(){
String str = ";a;b;c\\;;d";
String delimiter = ";";
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
String[] arr = {"","a","b","c;","d"};
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testWhenSlashIsTheDelimiter(){
String str = "a\\b\\c";
String delimiter = "\\";
String[] arr = {"a","b","c"};
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testWhenSlashIsTheDelimiterAndStartWithIt(){
String str = "\\a\\b\\c";
String delimiter = "\\";
String[] arr = {"","a","b","c"};
List<String> list = SplitStringUtil.splitStringIntoList(str, delimiter);
for(int i=0;i<arr.length;i++){
assertEquals(arr[i],list.get(i));
}
}
@Test
public void testRemoveSlashFromCharArr(){
char[] arr = {'a','b','\\','c','\\','d'};
char [] target = {'a','b','c','d'};
char [] res = SplitStringUtil.removeSlashFromCharArr(arr, 0, arr.length);
for(int i=0;i<target.length;i++){
assertEquals(target[i],res[i]);
}
}
@Test
public void testRemoveSlashFromCharArrZero(){
char[] arr = {'a','b','\\','c','\\','d'};
char [] target = {'a','b','c','d'};
char [] res = SplitStringUtil.removeSlashFromCharArr(arr, 0, arr.length);
for(int i=0;i<target.length;i++){
assertEquals(target[i],res[i]);
}
}
}