Javadoc errors when publishing artifacts

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.9.1:javadoc (default-cli) on project tephra-api: An error has occurred in JavaDocs report generation:
[ERROR] Exit code: 1 - /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:151: warning: no @return
[ERROR] public long getTransactionId() {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:160: warning: no @return
[ERROR] public long getWritePointer() {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:199: warning: no @param for version
[ERROR] public boolean isInProgress(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:199: warning: no @return
[ERROR] public boolean isInProgress(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:207: warning: no @param for version
[ERROR] public boolean isExcluded(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:207: warning: no @return
[ERROR] public boolean isExcluded(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:216: warning: no @param for version
[ERROR] public boolean isCheckpoint(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:216: warning: no @return
[ERROR] public boolean isCheckpoint(long version) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:250: warning: no @param for level
[ERROR] public void setVisibility(VisibilityLevel level) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:257: warning: no @return
[ERROR] public VisibilityLevel getVisibilityLevel() {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:275: warning: no @return
[ERROR] public long[] getCheckpointWritePointers() {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:49: warning: empty <p> tag
[ERROR] * <p>
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/Transaction.java:60: error: unexpected end tag: </p>
[ERROR] * </p>
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:87: warning: no @throws for java.lang.Exception
[ERROR] boolean commitTx() throws Exception;
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:105: warning: no @throws for java.lang.Exception
[ERROR] boolean rollbackTx() throws Exception;
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:111: warning: no @return
[ERROR] String getTransactionAwareName();
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:25: error: self-closing element not allowed
[ERROR] * <p/>
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:34: error: malformed HTML
[ERROR] *  Collection<byte[]> changes = dataSet.getTxChanges();
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionAware.java:34: error: bad use of '>'
[ERROR] *  Collection<byte[]> changes = dataSet.getTxChanges();
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionConflictException.java:34: warning: no @param for message
[ERROR] public TransactionConflictException(String message) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionConflictException.java:45: warning: no @param for message
[ERROR] public TransactionConflictException(String message, Throwable cause) {
[ERROR] ^
[ERROR] /Users/andreas/apache/incubator-tephra/tephra-api/src/main/java/org/apache/tephra/TransactionConflictException.java:45: warning: no @param for cause
[ERROR] public TransactionConflictException(String message, Throwable cause) {
[ERROR] ^
[ERROR] 
[ERROR] Command line was: /Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/bin/javadoc @options @packages
[ERROR] 
[ERROR] Refer to the generated Javadoc files in '/Users/andreas/apache/incubator-tephra/tephra-api/target/site/apidocs' dir.
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <goals> -rf :tephra-api