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AudricVAudricV
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Do some code improvements
Use final where possible, annotate some methods and parameters as Nonnull and format new code to be in the 100 characters limit per line.
1 parent 1c30a27 commit 3205514

4 files changed

Lines changed: 51 additions & 32 deletions

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‎extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeJavaScriptExtractor.java‎

Lines changed: 21 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -12,11 +12,12 @@
1212
import javax.annotation.Nonnull;
1313

1414
/**
15-
* YouTube restricts streaming their media in multiple ways by requiring clients to apply a cipher function
16-
* on parameters of requests.
15+
* YouTube restricts streaming their media in multiple ways by requiring clients to apply a cipher
16+
* function on parameters of requests.
1717
* The cipher function is sent alongside as a JavaScript function.
1818
* <p>
19-
* This class handling fetching the JavaScript file in order to allow other classes to extract the needed functions.
19+
* This class handling fetching the JavaScript file in order to allow other classes to extract the
20+
* needed functions.
2021
*/
2122
public class YoutubeJavaScriptExtractor {
2223

@@ -27,14 +28,16 @@ private YoutubeJavaScriptExtractor() {
2728
}
2829

2930
/**
30-
* Extracts the JavaScript file. The result is cached, so subsequent calls use the result of previous calls.
31+
* Extracts the JavaScript file. The result is cached, so subsequent calls use the result of
32+
* previous calls.
3133
*
32-
* @param videoId Does not influence the result, but a valid video id may help in the chance that YouTube tracks it.
33-
* @return The whole javascript file as a string.
34+
* @param videoId Does not influence the result, but a valid video id may help in the chance
35+
* that YouTube tracks it.
36+
* @return The whole JavaScript file as a string.
3437
* @throws ParsingException If the extraction failed.
3538
*/
3639
@Nonnull
37-
public static String extractJavaScriptCode(String videoId) throws ParsingException {
40+
public static String extractJavaScriptCode(final String videoId) throws ParsingException {
3841
if (cachedJavaScriptCode == null) {
3942
final String playerJsUrl = YoutubeJavaScriptExtractor.cleanJavaScriptUrl(
4043
YoutubeJavaScriptExtractor.extractJavaScriptUrl(videoId));
@@ -45,18 +48,19 @@ public static String extractJavaScriptCode(String videoId) throws ParsingExcepti
4548
}
4649

4750
/**
48-
* Same as {@link YoutubeJavaScriptExtractor#extractJavaScriptCode(String)} but with a constant value for videoId.
51+
* Same as {@link YoutubeJavaScriptExtractor#extractJavaScriptCode(String)} but with a constant
52+
* value for videoId.
4953
* Possible because the videoId has no influence on the result.
5054
* <p>
51-
* In the off chance that YouTube tracks with which video id the request is made, it may make sense to pass in
52-
* video ids.
55+
* In the off chance that YouTube tracks with which video id the request is made, it may make
56+
* sense to pass in video ids.
5357
*/
5458
@Nonnull
5559
public static String extractJavaScriptCode() throws ParsingException {
5660
return extractJavaScriptCode("d4IGg5dqeO8");
5761
}
5862

59-
private static String extractJavaScriptUrl(String videoId) throws ParsingException {
63+
private static String extractJavaScriptUrl(final String videoId) throws ParsingException {
6064
try {
6165
final String embedUrl = "https://www.youtube.com/embed/" + videoId;
6266
final String embedPageContent = NewPipe.getDownloader()
@@ -84,7 +88,8 @@ private static String extractJavaScriptUrl(String videoId) throws ParsingExcepti
8488
throw new ParsingException("Embedded info did not provide YouTube player js url");
8589
}
8690

87-
private static String cleanJavaScriptUrl(String playerJsUrl) {
91+
@Nonnull
92+
private static String cleanJavaScriptUrl(@Nonnull final String playerJsUrl) {
8893
if (playerJsUrl.startsWith("//")) {
8994
return HTTPS + playerJsUrl;
9095
} else if (playerJsUrl.startsWith("/")) {
@@ -95,10 +100,12 @@ private static String cleanJavaScriptUrl(String playerJsUrl) {
95100
}
96101
}
97102

98-
private static String downloadJavaScriptCode(String playerJsUrl) throws ParsingException {
103+
@Nonnull
104+
private static String downloadJavaScriptCode(final String playerJsUrl)
105+
throws ParsingException {
99106
try {
100107
return NewPipe.getDownloader().get(playerJsUrl, Localization.DEFAULT).responseBody();
101-
} catch (Exception e) {
108+
} catch (final Exception e) {
102109
throw new ParsingException("Could not get player js code from url: " + playerJsUrl);
103110
}
104111
}

‎extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeThrottlingDecrypter.java‎

Lines changed: 22 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -4,6 +4,7 @@
44
import org.schabi.newpipe.extractor.utils.JavaScript;
55
import org.schabi.newpipe.extractor.utils.Parser;
66

7+
import javax.annotation.Nonnull;
78
import java.util.HashMap;
89
import java.util.Map;
910
import java.util.regex.Pattern;
@@ -33,11 +34,12 @@ public class YoutubeThrottlingDecrypter {
3334

3435
/**
3536
* <p>
36-
* Use this if you care about the off chance that YouTube tracks with which videoId the cipher is requested.
37+
* Use this if you care about the off chance that YouTube tracks with which videoId the cipher
38+
* is requested.
3739
* </p>
3840
* Otherwise use the no-arg constructor which uses a constant value.
3941
*/
40-
public YoutubeThrottlingDecrypter(String videoId) throws ParsingException {
42+
public YoutubeThrottlingDecrypter(final String videoId) throws ParsingException {
4143
final String playerJsCode = YoutubeJavaScriptExtractor.extractJavaScriptCode(videoId);
4244

4345
functionName = parseDecodeFunctionName(playerJsCode);
@@ -51,17 +53,22 @@ public YoutubeThrottlingDecrypter() throws ParsingException {
5153
function = parseDecodeFunction(playerJsCode, functionName);
5254
}
5355

54-
private String parseDecodeFunctionName(String playerJsCode) throws Parser.RegexException {
55-
Pattern pattern = Pattern.compile("b=a\\.get\\(\"n\"\\)\\)&&\\(b=(\\w+)\\(b\\),a\\.set\\(\"n\",b\\)");
56+
private String parseDecodeFunctionName(final String playerJsCode)
57+
throws Parser.RegexException {
58+
Pattern pattern = Pattern.compile(
59+
"b=a\\.get\\(\"n\"\\)\\)&&\\(b=(\\w+)\\(b\\),a\\.set\\(\"n\",b\\)");
5660
return Parser.matchGroup1(pattern, playerJsCode);
5761
}
5862

59-
private String parseDecodeFunction(String playerJsCode, String functionName) throws Parser.RegexException {
60-
Pattern functionPattern = Pattern.compile(functionName + "=function(.*?;)\n", Pattern.DOTALL);
61-
return "function " + functionName + Parser.matchGroup1(functionPattern, playerJsCode);
63+
@Nonnull
64+
private String parseDecodeFunction(final String playerJsCode, final String functionName)
65+
throws Parser.RegexException {
66+
Pattern functionPattern = Pattern.compile(functionName + "=function(.*?;)\n",
67+
Pattern.DOTALL);
68+
return "function " + functionName + Parser.matchGroup1(functionPattern, playerJsCode);
6269
}
6370

64-
public String apply(String url) throws Parser.RegexException {
71+
public String apply(final String url) throws Parser.RegexException {
6572
if (containsNParam(url)) {
6673
String oldNParam = parseNParam(url);
6774
String newNParam = decryptNParam(oldNParam);
@@ -71,16 +78,16 @@ public String apply(String url) throws Parser.RegexException {
7178
}
7279
}
7380

74-
private boolean containsNParam(String url) {
81+
private boolean containsNParam(final String url) {
7582
return Parser.isMatch(N_PARAM_REGEX, url);
7683
}
7784

78-
private String parseNParam(String url) throws Parser.RegexException {
85+
private String parseNParam(final String url) throws Parser.RegexException {
7986
Pattern nValuePattern = Pattern.compile(N_PARAM_REGEX);
8087
return Parser.matchGroup1(nValuePattern, url);
8188
}
8289

83-
private String decryptNParam(String nParam) {
90+
private String decryptNParam(final String nParam) {
8491
if (nParams.containsKey(nParam)) {
8592
return nParams.get(nParam);
8693
}
@@ -89,7 +96,10 @@ private String decryptNParam(String nParam) {
8996
return decryptedNParam;
9097
}
9198

92-
private String replaceNParam(String url, String oldValue, String newValue) {
99+
@Nonnull
100+
private String replaceNParam(@Nonnull final String url,
101+
final String oldValue,
102+
final String newValue) {
93103
return url.replace(oldValue, newValue);
94104
}
95105
}

‎extractor/src/main/java/org/schabi/newpipe/extractor/utils/JavaScript.java‎

Lines changed: 7 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -9,15 +9,17 @@ public class JavaScript {
99
private JavaScript() {
1010
}
1111

12-
public static String run(String function, String functionName, String... parameters) {
12+
public static String run(final String function,
13+
final String functionName,
14+
final String... parameters) {
1315
try {
14-
Context context = Context.enter();
16+
final Context context = Context.enter();
1517
context.setOptimizationLevel(-1);
16-
ScriptableObject scope = context.initSafeStandardObjects();
18+
final ScriptableObject scope = context.initSafeStandardObjects();
1719

1820
context.evaluateString(scope, function, functionName, 1, null);
19-
Function jsFunction = (Function) scope.get(functionName, scope);
20-
Object result = jsFunction.call(context, scope, scope, parameters);
21+
final Function jsFunction = (Function) scope.get(functionName, scope);
22+
final Object result = jsFunction.call(context, scope, scope, parameters);
2123
return result.toString();
2224
} finally {
2325
Context.exit();

‎extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeJavaScriptExtractorTest.java‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -38,7 +38,7 @@ public void testExtractJavaScript__invalidVideoId__success() throws ParsingExcep
3838

3939
}
4040

41-
private void assertPlayerJsCode(String playerJsCode) {
41+
private void assertPlayerJsCode(final String playerJsCode) {
4242
assertThat(playerJsCode, allOf(
4343
containsString(" Copyright The Closure Library Authors.\n"
4444
+ " SPDX-License-Identifier: Apache-2.0"),

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