# Java Building Preferences

Indicate your preferences for the Building settings on the Java > Compiler > Building preference page.

### General

Option | Description | Default
--- | --- | ---
Maximum number of reported problems per compilation unit | Specifies how many problems should be reported for a compilation unit. | 100
Enable use of exclusion patterns in source folders | When disabled, no entry on a project classpath can be associated with an exclusion pattern. | On
Enable use of multiple output locations for source folders | When disabled, no entry on a project classpath can be associated with a specific output location, preventing thus usage of multiple output locations. | On

### Build path problems

Abort build when build path errors occur | Allow to toggle the builder to abort if the classpath is invalid. | On
Incomplete build path | Indicate the severity of the problem reported when an entry on the classpath does not exist, is not legitimate or is not visible (e.g. a reference project is closed). | Error
Circular dependencies | Indicate the severity of the problem reported when a project is involved in a cycle. | Error
Incompatible required binaries | Indicate the severity of the problem reported when a project requires another project or library with an incompatible target JDK level (e.g. a project using 1.4 compiler compliance, but compiled against 1.5 system libraries on the build path). | Ignore
Output location overlaps source location | Indicated the severity of the problem reported when a source entry's output location overlaps another source entry. | Error

No strictly compatible JRE for execution environment available

Indicate the severity of the problem reported when project's build path contains an execution environment for which there is no strictly compatible JRE available in the workspace (e.g. a project using execution environment JavaSE-1.6 as JRE System Library, but the only Installed JREs available in the preferences are 1.7 and 1.8.

Ignore

Compiler Compliance does not match used JRE

Indicate the severity of the problem reported when project's used JRE does not match the compiler compliance level selected. (e.g. a project using JRE 1.8 as JRE System Library, and the compiler compliance is set to 1.7). If the JRE being used is 9 or above and the --release option is selected and even if the complier compliance does not match the JRE being used, this option will be ignored.

Warning

### Output folder

Duplicated resources | Indicate the severity of the problem reported when more than one occurrence of a resource is to be copied into the output location. | Warning
Scrub output folders when cleaning projects | Indicate whether the Java Builder is allowed to clean the output folders when performing full build operations. | On
Rebuild class files modified by others | Indicate whether class files which have been modified by others should be rebuilt to undo the modification. | Off
Filtered resources | A comma separated list of file patterns which are not copied to the output folder. | Empty

Java builder
Inclusion and exclusion patterns
Build classpath