Make getters and setters null-safety consistent

This commit ensure that null-safety is consistent between
getters and setters in order to be able to provide beans
with properties with a common type when type safety is
taken in account like with Kotlin.

It also add a few missing property level @Nullable
annotations.

Issue: SPR-15792

spring-context-support/src/main/java/org/springframework/cache/ehcache/EhCacheCacheManager.java

@@ -37,6 +37,7 @@ import org.springframework.util.Assert;
  */
 public class EhCacheCacheManager extends AbstractTransactionSupportingCacheManager {
 
+	@Nullable
 	private net.sf.ehcache.CacheManager cacheManager;
 
 
@@ -59,7 +60,7 @@ public class EhCacheCacheManager extends AbstractTransactionSupportingCacheManag
 	/**
 	 * Set the backing EhCache {@link net.sf.ehcache.CacheManager}.
 	 */
-	public void setCacheManager(net.sf.ehcache.CacheManager cacheManager) {
+	public void setCacheManager(@Nullable net.sf.ehcache.CacheManager cacheManager) {
 		this.cacheManager = cacheManager;
 	}
 

spring-context-support/src/main/java/org/springframework/cache/jcache/JCacheCacheManager.java

@@ -38,6 +38,7 @@ import org.springframework.util.Assert;
  */
 public class JCacheCacheManager extends AbstractTransactionSupportingCacheManager {
 
+	@Nullable
 	private javax.cache.CacheManager cacheManager;
 
 	private boolean allowNullValues = true;
@@ -62,7 +63,7 @@ public class JCacheCacheManager extends AbstractTransactionSupportingCacheManage
 	/**
 	 * Set the backing JCache {@link javax.cache.CacheManager}.
 	 */
-	public void setCacheManager(javax.cache.CacheManager cacheManager) {
+	public void setCacheManager(@Nullable javax.cache.CacheManager cacheManager) {
 		this.cacheManager = cacheManager;
 	}
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/DefaultJCacheOperationSource.java

@@ -63,7 +63,7 @@ public class DefaultJCacheOperationSource extends AnnotationJCacheOperationSourc
 	 * Set the default {@link CacheManager} to use to lookup cache by name. Only mandatory
 	 * if the {@linkplain CacheResolver cache resolvers} have not been set.
 	 */
-	public void setCacheManager(CacheManager cacheManager) {
+	public void setCacheManager(@Nullable CacheManager cacheManager) {
 		this.cacheManager = cacheManager;
 	}
 
@@ -79,7 +79,7 @@ public class DefaultJCacheOperationSource extends AnnotationJCacheOperationSourc
 	 * Set the {@link CacheResolver} to resolve regular caches. If none is set, a default
 	 * implementation using the specified cache manager will be used.
 	 */
-	public void setCacheResolver(CacheResolver cacheResolver) {
+	public void setCacheResolver(@Nullable CacheResolver cacheResolver) {
 		this.cacheResolver = cacheResolver;
 	}
 
@@ -95,7 +95,7 @@ public class DefaultJCacheOperationSource extends AnnotationJCacheOperationSourc
 	 * Set the {@link CacheResolver} to resolve exception caches. If none is set, a default
 	 * implementation using the specified cache manager will be used.
 	 */
-	public void setExceptionCacheResolver(CacheResolver exceptionCacheResolver) {
+	public void setExceptionCacheResolver(@Nullable CacheResolver exceptionCacheResolver) {
 		this.exceptionCacheResolver = exceptionCacheResolver;
 	}
 
@@ -112,7 +112,7 @@ public class DefaultJCacheOperationSource extends AnnotationJCacheOperationSourc
 	 * honoring the JSR-107 {@link javax.cache.annotation.CacheKey} and
 	 * {@link javax.cache.annotation.CacheValue} will be used.
 	 */
-	public void setKeyGenerator(KeyGenerator keyGenerator) {
+	public void setKeyGenerator(@Nullable KeyGenerator keyGenerator) {
 		this.keyGenerator = keyGenerator;
 	}
 

spring-context-support/src/main/java/org/springframework/mail/SimpleMailMessage.java

@@ -98,7 +98,7 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 
 
 	@Override
-	public void setFrom(String from) {
+	public void setFrom(@Nullable String from) {
 		this.from = from;
 	}
 
@@ -108,7 +108,7 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setReplyTo(String replyTo) {
+	public void setReplyTo(@Nullable String replyTo) {
 		this.replyTo = replyTo;
 	}
 
@@ -118,12 +118,12 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setTo(String to) {
+	public void setTo(@Nullable String to) {
 		this.to = new String[] {to};
 	}
 
 	@Override
-	public void setTo(String[] to) {
+	public void setTo(@Nullable String[] to) {
 		this.to = to;
 	}
 
@@ -133,12 +133,12 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setCc(String cc) {
+	public void setCc(@Nullable String cc) {
 		this.cc = new String[] {cc};
 	}
 
 	@Override
-	public void setCc(String[] cc) {
+	public void setCc(@Nullable String[] cc) {
 		this.cc = cc;
 	}
 
@@ -148,12 +148,12 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setBcc(String bcc) {
+	public void setBcc(@Nullable String bcc) {
 		this.bcc = new String[] {bcc};
 	}
 
 	@Override
-	public void setBcc(String[] bcc) {
+	public void setBcc(@Nullable String[] bcc) {
 		this.bcc = bcc;
 	}
 
@@ -163,7 +163,7 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setSentDate(Date sentDate) {
+	public void setSentDate(@Nullable Date sentDate) {
 		this.sentDate = sentDate;
 	}
 
@@ -173,7 +173,7 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setSubject(String subject) {
+	public void setSubject(@Nullable String subject) {
 		this.subject = subject;
 	}
 
@@ -183,7 +183,7 @@ public class SimpleMailMessage implements MailMessage, Serializable {
 	}
 
 	@Override
-	public void setText(String text) {
+	public void setText(@Nullable String text) {
 		this.text = text;
 	}
 

spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java

@@ -99,6 +99,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	@Nullable
 	private String defaultEncoding;
 
+	@Nullable
 	private FileTypeMap defaultFileTypeMap;
 
 
@@ -165,7 +166,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	/**
 	 * Set the mail protocol. Default is "smtp".
 	 */
-	public void setProtocol(String protocol) {
+	public void setProtocol(@Nullable String protocol) {
 		this.protocol = protocol;
 	}
 
@@ -181,7 +182,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	 * Set the mail server host, typically an SMTP host.
 	 * <p>Default is the default host of the underlying JavaMail Session.
 	 */
-	public void setHost(String host) {
+	public void setHost(@Nullable String host) {
 		this.host = host;
 	}
 
@@ -220,7 +221,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	 * @see #setSession
 	 * @see #setPassword
 	 */
-	public void setUsername(String username) {
+	public void setUsername(@Nullable String username) {
 		this.username = username;
 	}
 
@@ -243,7 +244,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	 * @see #setSession
 	 * @see #setUsername
 	 */
-	public void setPassword(String password) {
+	public void setPassword(@Nullable String password) {
 		this.password = password;
 	}
 
@@ -260,7 +261,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	 * created by this instance.
 	 * <p>Such an encoding will be auto-detected by {@link MimeMessageHelper}.
 	 */
-	public void setDefaultEncoding(String defaultEncoding) {
+	public void setDefaultEncoding(@Nullable String defaultEncoding) {
 		this.defaultEncoding = defaultEncoding;
 	}
 
@@ -286,7 +287,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 	 * {@code mime.types} file contained in the Spring jar).
 	 * @see MimeMessageHelper#setFileTypeMap
 	 */
-	public void setDefaultFileTypeMap(FileTypeMap defaultFileTypeMap) {
+	public void setDefaultFileTypeMap(@Nullable FileTypeMap defaultFileTypeMap) {
 		this.defaultFileTypeMap = defaultFileTypeMap;
 	}