# How to build project
This document helps people to compile and build the project in your maven and set your IDE.
## Build Project
**Because we are using Git submodule, we recommend don't use `GitHub` tag or release page to download source codes for compiling.**
### Build from GitHub
1. Prepare git, JDK8 and maven3
1. `git clone https://github.com/apache/skywalking.git`
1. `cd skywalking/`
1. Switch to the tag by using `git checkout [tagname]` (Optional, switch if want to build a release from source codes)
1. `git submodule init`
1. `git submodule update`
1. Run `./mvnw clean package -DskipTests`
1. All packages are in `/dist` (.tar.gz for Linux and .zip for Windows).
### Build from Apache source code release
- What is `Apache source code release`?
For each official Apache release, there is a complete and independent source code tar, which is including all source codes. You could download it from [SkyWalking Apache download page](http://skywalking.apache.org/downloads/). No git related stuff required when compiling this. Just follow these steps.
1. Prepare JDK8 and maven3
1. Run `./mvnw clean package -DskipTests`
1. All packages are in `/dist`.(.tar.gz for Linux and .zip for Windows).
### Advanced compile
SkyWalking is a complex maven project, including many modules, which could cause long compiling time.
If you just want to recompile part of the project, you have following options
- Compile agent and package
> ./mvnw package -Pagent,dist
- Compile backend and package
> ./mvnw package -Pbackend,dist
- Compile UI and package
> ./mvnw package -Pui,dist
## Setup your IntelliJ IDEA
1. Import the project as a maven project
1. Run `./mvnw compile -Dmaven.test.skip=true` to compile project and generate source codes. Because we use gRPC and protobuf.
1. Set **Generated Source Codes** folders.
* `grpc-java` and `java` folders in **apm-protocol/apm-network/target/generated-sources/protobuf**
* `grpc-java` and `java` folders in **oap-server/server-core/target/generated-sources/protobuf**
* `grpc-java` and `java` folders in **oap-server/server-receiver-plugin/receiver-proto/target/generated-sources/protobuf**
* `grpc-java` and `java` folders in **oap-server/exporter/target/generated-sources/protobuf**
* `antlr4` folder in **oap-server/generate-tool-grammar/target/generated-sources**
* `oal` folder in **oap-server/generated-analysis/target/generated-sources**
## Setup your Eclipse IDE
1. Import the project as a maven project
2. For supporting multiple source directories, you need to add the following configuration in `skywalking/pom.xml` file:
```
org.codehaus.mojobuild-helper-maven-plugin1.8add-sourcegenerate-sourcesadd-sourcesrc/java/mainapm-protocol/apm-network/target/generated-sources/protobufapm-collector/apm-collector-remote/collector-remote-grpc-provider/target/generated-sources/protobuf
```
3. Add the following configuration under to let eclipse's M2e plug-in supports execution's solution configuration
```
org.eclipse.m2elifecycle-mapping1.0.0org.codehaus.mojobuild-helper-maven-plugin[1.8,)add-source
```
4. Adding Google guava dependency to apm-collector-remote/collector-remote-grpc-provider/pom.xml files
```
com.google.guavaguava24.0-jre
```
5. Run `./mvnw compile -Dmaven.test.skip=true`
6. Run `maven update`. Must remove the clean projects item before maven update(This will be clear the proto conversion Java file generated by the complie)
7. Run `./mvnw compile` complie collector-remote-grpc-provider and apm-protocol
8. Refresh project