Showing 638 of 638 total issues
Replace this use of System.out or System.err by a logger. Open
System.out.print("k Spanning Tree (k=2): ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
This block of commented-out lines of code should be removed. Open
* Licensed under the Apache License, Version 2.0 (the "License");
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Programmers should not comment out code as it bloats programs and reduces readability.
Unused code should be deleted and can be retrieved from source control history if required.
Replace this use of System.out or System.err by a logger. Open
System.out.print("Empty: ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.print("Spectral Clustering (k=2): ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.println(graph);
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.print("Graph: ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.println(maxmax.getClustering().getDigraph());
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.print("MaxMax: ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.print("MaxMax Digraph: ");
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- Exclude checks
When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Replace this use of System.out or System.err by a logger. Open
System.out.print("Chinese Whispers: ");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Define a constant instead of duplicating this literal "parameters are not initialized" 3 times. Open
this.parameters = requireNonNull(parameters, "parameters are not initialized");
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Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.
On the other hand, constants can be referenced from many places, but only need to be updated in a single place.
Noncompliant Code Example
With the default threshold of 3:
public void run() { prepare("action1"); // Noncompliant - "action1" is duplicated 3 times execute("action1"); release("action1"); } @SuppressWarning("all") // Compliant - annotations are excluded private void method1() { /* ... */ } @SuppressWarning("all") private void method2() { /* ... */ } public String method3(String a) { System.out.println("'" + a + "'"); // Compliant - literal "'" has less than 5 characters and is excluded return ""; // Compliant - literal "" has less than 5 characters and is excluded }
Compliant Solution
private static final String ACTION_1 = "action1"; // Compliant public void run() { prepare(ACTION_1); // Compliant execute(ACTION_1); release(ACTION_1); }
Exceptions
To prevent generating some false-positives, literals having less than 5 characters are excluded.
Replace this call to "replaceAll()" by a call to the "replace()" method. Open
replaceAll("MCL", ProvidingAlgorithm.CHINESE_WHISPERS.name());
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The underlying implementation of String::replaceAll
calls the java.util.regex.Pattern.compile()
method each time it is
called even if the first argument is not a regular expression. This has a significant performance cost and therefore should be used with care.
When String::replaceAll
is used, the first argument should be a real regular expression. If it’s not the case,
String::replace
does exactly the same thing as String::replaceAll
without the performance drawback of the regex.
This rule raises an issue for each String::replaceAll
used with a String
as first parameter which doesn’t contains
special regex character or pattern.
Noncompliant Code Example
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replaceAll("Bob is", "It's"); // Noncompliant changed = changed.replaceAll("\\.\\.\\.", ";"); // Noncompliant
Compliant Solution
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replace("Bob is", "It's"); changed = changed.replace("...", ";");
Or, with a regex:
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replaceAll("\\w*\\sis", "It's"); changed = changed.replaceAll("\\.{3}", ";");
See
- {rule:java:S4248} - Regex patterns should not be created needlessly
Replace this use of System.out or System.err by a logger. Open
System.out.println();
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data
Remove this useless assignment to local variable "ego". Open
final var ego = Neighbors.graph(graph, requireNonNull(target));
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A dead store happens when a local variable is assigned a value that is not read by any subsequent instruction. Calculating or retrieving a value only to then overwrite it or throw it away, could indicate a serious error in the code. Even if it's not an error, it is at best a waste of resources. Therefore all calculated values should be used.
Noncompliant Code Example
i = a + b; // Noncompliant; calculation result not used before value is overwritten i = compute();
Compliant Solution
i = a + b; i += compute();
Exceptions
This rule ignores initializations to -1, 0, 1, null
, true
, false
and ""
.
See
- MITRE, CWE-563 - Assignment to Variable without Use ('Unused Variable')
- CERT, MSC13-C. - Detect and remove unused values
- CERT, MSC56-J. - Detect and remove superfluous code and values
Remove this useless assignment to local variable "clusters". Open
final Iterable<Set<String>> clusters = () -> clustering.getClusters().stream().
sorted((smaller, larger) -> Integer.compare(larger.size(), smaller.size())).
iterator();
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A dead store happens when a local variable is assigned a value that is not read by any subsequent instruction. Calculating or retrieving a value only to then overwrite it or throw it away, could indicate a serious error in the code. Even if it's not an error, it is at best a waste of resources. Therefore all calculated values should be used.
Noncompliant Code Example
i = a + b; // Noncompliant; calculation result not used before value is overwritten i = compute();
Compliant Solution
i = a + b; i += compute();
Exceptions
This rule ignores initializations to -1, 0, 1, null
, true
, false
and ""
.
See
- MITRE, CWE-563 - Assignment to Variable without Use ('Unused Variable')
- CERT, MSC13-C. - Detect and remove unused values
- CERT, MSC56-J. - Detect and remove superfluous code and values
Replace this call to "replaceAll()" by a call to the "replace()" method. Open
replaceAll("-", "_").
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- Exclude checks
The underlying implementation of String::replaceAll
calls the java.util.regex.Pattern.compile()
method each time it is
called even if the first argument is not a regular expression. This has a significant performance cost and therefore should be used with care.
When String::replaceAll
is used, the first argument should be a real regular expression. If it’s not the case,
String::replace
does exactly the same thing as String::replaceAll
without the performance drawback of the regex.
This rule raises an issue for each String::replaceAll
used with a String
as first parameter which doesn’t contains
special regex character or pattern.
Noncompliant Code Example
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replaceAll("Bob is", "It's"); // Noncompliant changed = changed.replaceAll("\\.\\.\\.", ";"); // Noncompliant
Compliant Solution
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replace("Bob is", "It's"); changed = changed.replace("...", ";");
Or, with a regex:
String init = "Bob is a Bird... Bob is a Plane... Bob is Superman!"; String changed = init.replaceAll("\\w*\\sis", "It's"); changed = changed.replaceAll("\\.{3}", ";");
See
- {rule:java:S4248} - Regex patterns should not be created needlessly
Don't try to be smarter than the JVM, remove this call to run the garbage collector. Open
System.gc();
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Calling System.gc()
or Runtime.getRuntime().gc()
is a bad idea for a simple reason: there is no way to know exactly what
will be done under the hood by the JVM because the behavior will depend on its vendor, version and options:
- Will the whole application be frozen during the call?
- Is the
-XX:DisableExplicitGC
option activated? - Will the JVM simply ignore the call?
- ...
Like for System.gc()
, there is no reason to manually call runFinalization()
to force the call of finalization methods of
any objects pending finalization.
An application relying on these unpredictable methods is also unpredictable and therefore broken. The task of running the garbage collector and
calling finalize()
methods should be left exclusively to the JVM.
Replace this use of System.out or System.err by a logger. Open
System.out.println(" Computational Linguistics 45(3), 423-479 (2019).");
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When logging a message there are several important requirements which must be fulfilled:
- The user must be able to easily retrieve the logs
- The format of all logged message must be uniform to allow the user to easily read the log
- Logged data must actually be recorded
- Sensitive data must only be logged securely
If a program directly writes to the standard outputs, there is absolutely no way to comply with those requirements. That's why defining and using a dedicated logger is highly recommended.
Noncompliant Code Example
System.out.println("My Message"); // Noncompliant
Compliant Solution
logger.log("My Message");
See
- CERT, ERR02-J. - Prevent exceptions while logging data