社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 11678阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* 5K|1Y#X  
**SiteFileFetch.java H.qp~-n  
*/ ?ntyF-n&  
package NetFox; W]{mEB  
import java.io.*; J'`,];su  
import java.net.*; R R<92R  
glbU\K> >  
_[zO?Div[  
public class SiteFileFetch extends Thread { /\"=egB9  
-&oJ@Aa  
`ySLic`  
SiteInfoBean siteInfoBean = null; //文件信息Bean zFmoo4P/  
long[] nStartPos; //开始位置 );$_|]#  
long[] nEndPos; //结束位置 N'w ;1,c+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 RR>Q$ K  
long nFileLength; //文件长度 T B~C4HK=  
boolean bFirst = true; //是否第一次取文件 c7.%Bn,  
boolean bStop = false; //停止标志 ~]a:9Ev*  
File tmpFile; //文件下载的临时信息 |f;u5r!^=  
DataOutputStream output; //输出到文件的输出流 Xs$k6C3  
]f=108|8  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) P#-Ye<V~J(  
public SiteFileFetch(SiteInfoBean bean) throws IOException d#cw`h<c~  
{ a^t#kdT  
siteInfoBean = bean; 2uu"0Rm%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %:yJ/&-Q,Z  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (Vnv"= (  
if(tmpFile.exists ()) :KGUO{_u  
{ V6)\;c  
bFirst = false; avrf]raM|  
read_nPos(); 7'\<\oT  
} g+|1khS)  
else f l*]ua  
{ }"BXqh"\`  
nStartPos = new long[bean.getNSplitter()]; gf7%vyMo$  
nEndPos = new long[bean.getNSplitter()]; RI9&KS  
} JK34pm[s  
7KXc9:p+  
>xb}AY;  
>/k[6r5  
} c,-3+b  
^cB83%<Z  
:t+XW`eQR:  
public void run() MgyV {`  
{ AAUFX/}8P  
//获得文件长度 A J<Sa=  
//分割文件 6Ty;m>j  
//实例FileSplitterFetch ?G%C}8a  
//启动FileSplitterFetch线程 MlVN'w  
//等待子线程返回 'F.Da#st!}  
try{ ^u`1W^>  
if(bFirst) *f{\ze@5=  
{ ,\ [R\s  
nFileLength = getFileSize(); YMx]i,u'+  
if(nFileLength == -1) M|nTO  
{ VgLrufJ  
System.err.println("File Length is not known!"); #lXwBfBMf  
} ;5QdT{$H  
else if(nFileLength == -2) H=O/w3  
{ jz;N&62|  
System.err.println("File is not access!"); g.$a]pZz  
} 7 06-QE^  
else Dz4e.tvN  
{ tGv5pe*r  
for(int i=0;i<nStartPos.length;i++) .BP@1K  
{ .&fG_(6|  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ErmlM#u  
} ;zk& 7P0  
for(int i=0;i<nEndPos.length-1;i++) [vCZoG8+>  
{ k'Is]=3  
nEndPos = nStartPos[i+1]; vJTdZ p  
} ^ z!g3  
nEndPos[nEndPos.length-1] = nFileLength; xe9E</M_  
} SbS*z:  
} VrDSN  
~.\CG'g  
u*LMpTnn  
//启动子线程 ;>YLL}]j  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b?S,%  
for(int i=0;i<nStartPos.length;i++) x UM,"+h  
{ OI:G~Wg  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?Vg251-H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jNRR=0  
nStartPos,nEndPos,i); RN2^=$'.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HoE@t-S  
fileSplitterFetch.start(); 5eS0 B{,c  
} {yFCGCs  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %@Mv-A6)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v;_m1UpuW  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (SMnYh4  
nEndPos = " + nFileLength); zM:&`6;e  
// fileSplitterFetch[nPos.length-1].start(); ]34fG3D|  
kF{'?R5 w  
I_ O8 9Sgn  
//等待子线程结束 ^\o3V<  
//int count = 0; {"f4oK{w  
//是否结束while循环 ppL*#/jYt  
boolean breakWhile = false; r2dU>U*:4  
[\|`C4@3a  
k2]fUP  
while(!bStop) va6e]p*Oy  
{ r:rM~``  
write_nPos(); i3 ?cL4  
Utility.sleep(500); n[|*[II  
breakWhile = true; K,B qVu  
S)`%clN}J  
\0bao<  
for(int i=0;i<nStartPos.length;i++) I$yFCdXr  
{ l=+hs  
if(!fileSplitterFetch.bDownOver) #GoZH?MAF  
{ 7S^ba  
breakWhile = false; wg-qq4Q\  
break; OGA_3|[S   
} .AHf]X0  
} ')G, +d^  
if(breakWhile) =17d7#-  
break; 0<ze'FbV]  
04o>POR  
K14FY2"  
//count++; jg)+]r/hS  
//if(count>4) 3:H[S_q  
// siteStop(); Mk=M)d`  
} r1pj-   
{S l#z }@s  
w^BF.Nu  
System.err.println("文件下载结束!"); ML:Zm~A1U  
} $G UCVxs  
catch(Exception e){e.printStackTrace ();}  Z|t`}lK  
} D^m`&asC  
. {\lbI  
oh^/)2W  
//获得文件长度 ORCG(N  
public long getFileSize() 3haR/Y N  
{ )~> C1<  
int nFileLength = -1; )s-[d_g  
try{ %?sPKOh3N}  
URL url = new URL(siteInfoBean.getSSiteURL()); q7#4e?1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g]$e-X@k  
httpConnection.setRequestProperty("User-Agent","NetFox"); +mu.W r  
|XGj97#M  
S1vUP5cZ  
int responseCode=httpConnection.getResponseCode(); NUN~T (  
if(responseCode>=400) 5I`_S Oa!  
{ '?gF9:  
processErrorCode(responseCode); Qq7%{`< }  
return -2; //-2 represent access is error ]?un'$%e  
} fpPB_P{Ua  
tZL|;K  
#B$r|rqamq  
String sHeader; s!g06F  
jx=5E6(h  
gRsV -qS  
for(int i=1;;i++) hD*83_S  
{ w %2|Po5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .`ZuUr  
//Utility.log(in.readLine()); @A.7`*i_  
sHeader=httpConnection.getHeaderFieldKey(i); uUIjntSF(  
if(sHeader!=null) 1#w'<}h#U  
{  k00&+C  
if(sHeader.equals("Content-Length")) E[=# Rw!*  
{ YqQAogy h  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O)FkpZc@9c  
break; evQk,;pIm  
} F!RzF7h1  
} IE*5p6IM~  
else ~[Fh+t(Y  
break; {SRv=g  
} Efa3{ 7>{  
} fD* ?JzVY  
catch(IOException e){e.printStackTrace ();} qx'F9I  
catch(Exception e){e.printStackTrace ();} #;(Q \  
yDORL| E'  
?PSJQ3BC|  
Utility.log(nFileLength); Tfytc$aQ  
:OKU@l|  
7`P1=`..  
return nFileLength; s +Q'\?  
} UCBx?9O/0  
$/)0iL{0  
<)]j;Tl  
//保存下载信息(文件指针位置) (?vKe5  
private void write_nPos() hfL8]d-  
{ Qd"R@+i  
try{ RD_l  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8mn zxtk  
output.writeInt(nStartPos.length); 9O{b8=\}  
for(int i=0;i<nStartPos.length;i++) JY0}#FtgV  
{ df R?O#JPU  
// output.writeLong(nPos); ?y|8bw<  
output.writeLong(fileSplitterFetch.nStartPos); CkeqK  
output.writeLong(fileSplitterFetch.nEndPos); H1or,>GoO  
} +ab#2~,)  
output.close(); 4|INy =<"t  
} E]gy5y  
catch(IOException e){e.printStackTrace ();} b8O }XB  
catch(Exception e){e.printStackTrace ();} 1,Uf-i  
} "8R\!i.  
_08y; _S  
5M= S7B3=  
//读取保存的下载信息(文件指针位置) &eIwlynm  
private void read_nPos() )J(@e4;Rv  
{ Y![//tg  
try{ 3FQXp  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~E3"s  
int nCount = input.readInt(); A4IPd  
nStartPos = new long[nCount]; WW3! ,ln_  
nEndPos = new long[nCount]; o%3VE8-  
for(int i=0;i<nStartPos.length;i++) j\%m6\{n|  
{ rhH !-`m  
nStartPos = input.readLong(); Sd?+j;/"  
nEndPos = input.readLong(); " o>` Y  
} 7 : .bqRu  
input.close(); eCy]ugsi%  
} Bc1MKE5  
catch(IOException e){e.printStackTrace ();} KKGwMJku}  
catch(Exception e){e.printStackTrace ();} JrJTIUf_  
} mKZ^FgG  
[W--%=Ou  
]D\p<4uepM  
private void processErrorCode(int nErrorCode) x)prI6YMv\  
{ yoVN|5  
System.err.println("Error Code : " + nErrorCode); [h@MA|  
} NB .&J7v  
g 6!#n  
&aWY{ ?_  
//停止文件下载 IfF&QBi  
public void siteStop() &Tn7  
{ 40Z/;,wp{  
bStop = true; *rmwTD"  
for(int i=0;i<nStartPos.length;i++) 9 :FzSD  
fileSplitterFetch.splitterStop(); uTIl} N  
l EsE]f  
1IeB_t  
} n,o;:c  
} idGhWV'  
//负责部分文件的抓取 J%ue{PL7  
**FileSplitterFetch.java a4D4*=!G0  
*/ }< m@82\  
package NetFox; hZDv5]V:0  
h@D</2>  
S X6P>:`  
import java.io.*; b1t7/q  
import java.net.*; L}.V`v{zc  
O\[Td  
BGZvgMxLJ  
public class FileSplitterFetch extends Thread { jY8u1z  
h| ]BA}D  
c69M   
String sURL; //File URL VsR`y]"g  
long nStartPos; //File Snippet Start Position R:FyCT_,  
long nEndPos; //File Snippet End Position *l\vqgv.Z  
int nThreadID; //Thread's ID %{K6   
boolean bDownOver = false; //Downing is over &Vi0.o  
boolean bStop = false; //Stop identical sAKQ.8$h*  
FileAccessI fileAccessI = null; //File Access interface #Cz6c%yK  
ey3;rY1  
hXM2B2[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G##^xFx  
{ ;WpPdR2  
this.sURL = sURL; !Knv/:+  
this.nStartPos = nStart; Co^a$K  
this.nEndPos = nEnd; ICI8xP}a?  
nThreadID = id; y1zep\-D  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ea2&7  
} K#],4OG  
G9uWn%5r  
KqT~MPl  
public void run() 8L}N,6gC4_  
{ Zjh9jvsW  
while(nStartPos < nEndPos && !bStop) ?FRQ!R  
{ 9,;+B8-A  
R@H}n3,  
~*Ir\wE  
try{ NurbioFL  
URL url = new URL(sURL); j[o5fr)L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >5!/&D.q  
httpConnection.setRequestProperty("User-Agent","NetFox"); J "dp?i  
String sProperty = "bytes="+nStartPos+"-"; ;o0o6pF  
httpConnection.setRequestProperty("RANGE",sProperty); 7f`x-iH!]7  
Utility.log(sProperty); )gAFz+  
w_ po47S4  
e{x|d?)8  
InputStream input = httpConnection.getInputStream(); kg_f;uk+  
//logResponseHead(httpConnection); Y)X58_En  
r ,,A%  
G ]mX+?  
byte[] b = new byte[1024];  p3r1lUw  
int nRead; f{[,!VG  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \w=7L- 8  
{ YJ{d\j  
nStartPos += fileAccessI.write(b,0,nRead); 1yIo 'i1  
//if(nThreadID == 1) .DkDMg1US  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7J%v""\1!  
} n!(g<"  
Q,A`"e#:  
|fk,&5s  
Utility.log("Thread " + nThreadID + " is over!"); ]Zf@NY  
bDownOver = true; .W+ F<]r  
//nPos = fileAccessI.write (b,0,nRead); WPM<Qv L  
} i#~1|2  
catch(Exception e){e.printStackTrace ();} ~Zd n#z\  
} r,4V SyZF\  
} tK|hC[  
cMEM}Qh T  
TIa`cU`  
//打印回应的头信息 |KFWW  
public void logResponseHead(HttpURLConnection con) \'L6m1UZ%  
{ D{,B[5  
for(int i=1;;i++) "lf_`4  
{ =`X ;fz  
String header=con.getHeaderFieldKey(i); )LYj,do  
if(header!=null) ab 1\nzpd  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &xqe8!FeA  
Utility.log(header+" : "+con.getHeaderField(header)); : |c,.uO  
else :l>T~&/98  
break; ku'%+svD  
} XabrX|B#  
} b+M[DwPw  
5W!E.fz*T  
6zLz<p?  
public void splitterStop() CW=-@W7  
{ EtH)E)  
bStop = true; ?mt$c6-  
} Ffm Q$>S  
| ~G;M*q  
LE Y Y{G?  
} j$]t`6gG  
z~oGd,  
Ac.z6]p  
/* EVj48  
**FileAccess.java I#Tl  
*//文件访问(定位,写) Hf %;FaJ=  
package NetFox; /d >fp  
import java.io.*; fXw%2wg  
A?;/]m;  
j86s[Dty  
public class FileAccessI implements Serializable{ xL>0&R  
i*Y/q-N|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 't{=n[  
RandomAccessFile oSavedFile; 5Tp n`2F  
long nPos; |U^ ff^]  
2uWzcy ?F  
5Kv=;o=U  
public FileAccessI() throws IOException 'EREut,>'  
{ h3 p 3~xq  
this("",0); "eQ96^'J  
} !*|CIxk(  
y::;e#.  
ORx,n7-  
public FileAccessI(String sName,long nPos) throws IOException igz:ek`  
{ Sjr(e}*  
oSavedFile = new RandomAccessFile(sName,"rw"); `bT{E.(T  
this.nPos = nPos; HXdPKS4q  
oSavedFile.seek(nPos); O|j5ulO}&"  
} )hQNIt3o_  
i%*x7zjY{  
h)wR[N]n  
public synchronized int write(byte[] b,int nStart,int nLen) 3<+l.Wly  
{ l}(~q!r  
int n = -1; O:7y-r0i  
try{ 6g$04C3tHi  
oSavedFile.write(b,nStart,nLen); ~*B1}#;  
n = nLen; z7PPwTBa  
} <tF]>(|M  
catch(IOException e) T"d]QYJS  
{ il-&d]AP  
e.printStackTrace (); 5Ll[vBW  
} LwGcy1F.  
x2ol   
RV(}\JU  
return n; +Kq>r|;  
} h'-TZXs0e1  
2|%30i,vV  
^1cqx]>E  
} Y5MHd>m  
}(tGjx]  
yJp& A  
/* W: ?-d{  
**SiteInfoBean.java WejY b;KS  
*/ W&!Yprr  
package NetFox; >uuX<\cW  
C#-x 3d-{  
cE*|8'rSf  
public class SiteInfoBean { QHs]~Ja  
5h> gz  
%?wuKZLnc  
private String sSiteURL; //Site's URL N{ 9<Tf*  
private String sFilePath; //Saved File's Path 6U /wFT!7$  
private String sFileName; //Saved File's Name a|7V{pp=M  
private int nSplitter; //Count of Splited Downloading File +u=xBhZ  
;C"J5RA  
p-7dJ  
public SiteInfoBean() v}_$9&|S  
{//nSplitter的缺省值为5 f8&=D4)-w  
//default value of nSplitter is 5 If&p$pAH?  
this("","","",5); C3_*o>8  
} {9l4 pT3  
`\Npu  
|M K-~ep  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v%FVz  
{ X&lkA (  
sSiteURL= sURL; ,!Hl@(  
sFilePath = sPath; #SqOJX~Q  
sFileName = sName; u\E.H5u27  
this.nSplitter = nSpiltter; 16 Xwtn72  
]Pd*w`R  
1OGlD+f  
} NfO0^^"  
uyA9`~p=#  
#* Hhe>  
public String getSSiteURL() gvU6p[D  
{ +.R-a+y3  
return sSiteURL; 8p211MQ<  
} c"z%AzUV'  
9/%|#b-z  
N4Lk3]  
public void setSSiteURL(String value) iK#{#ebAoW  
{ aFSZYyPxwv  
sSiteURL = value; ,f1wN{P  
} e!-'O0-Kw  
HIU@m<  
|-|BM'Y  
public String getSFilePath() A |&EI-In  
{ VC+\RB#:-  
return sFilePath; ;|^fAc~9{r  
} -12v/an]L7  
1=D!C lcb  
lR(&Wc\j  
public void setSFilePath(String value) ?SAi t Q3  
{ qQ_B[?+W  
sFilePath = value; i Bi/9  
} UB1/FM4~  
W#wM PsB  
"D k:r/  
public String getSFileName() 5[R}MhLZ  
{ TB[vpTC9)  
return sFileName; E7<:>Uh  
} `Q8 D[  
Z kS* CG   
Kq?7#,_  
public void setSFileName(String value) m88~+o<G%  
{ 1)R)+`y  
sFileName = value; z%KChU  
} qb<gh D=j  
s_[?(Ip{  
S3<v?tqLr  
public int getNSplitter() b#m47yTW9<  
{ Gs6 #aL}]R  
return nSplitter; r%#qbsN  
} ~4^e a  
g3Q #B7A  
yS43>UK_W+  
public void setNSplitter(int nCount) Yru[{h8hw`  
{ 4TKi)0 #7  
nSplitter = nCount; }cT}G;L'-  
} 3pp w_?k  
} R3PhKdQ"  
+{I\r|  
Q.\>+4]1&&  
/* QD<4(@c5|  
**Utility.java ayD\b6Z2.  
*/ [GuDMl3hC  
package NetFox; \f  LBw0  
}B- A*TI<h  
Dpd$&Wr0Y  
public class Utility { UE4#j \  
pUr[MnQLf  
7" [;M  
public Utility() ts]7 + 6V  
{ .9xGLmg  
Ae#6=]V+^  
MH?B .2  
} r Lh h  
=<05PB  
//线程睡眠 _:L*{=N  
public static void sleep(int nSecond) K)?^b|D  
{ ~c^-DAgB  
try{ rYJ ))@  
Thread.sleep(nSecond); R}>Do=hAO  
} B`F82_O  
catch(Exception e) yjq )}y,tF  
{ D:(f"  
e.printStackTrace (); >DRs(~|V#  
} vFOv IVp  
} XbC8t &Q],  
&J b.OCf  
//日志 7N"Bbl  
public static void log(String sMsg) .;2!c'mT9  
{ IT(c'}  
System.err.println(sMsg); M\&~Dmd  
} UjaC( c  
 ~^S-  
aK{\8L3]  
public static void log(int sMsg) mSfhl(<L  
{ l.x }I"tf  
System.err.println(sMsg); ECScx02  
} !iVFzG @m  
} )ta5y7np  
6dL>Rzl$Dk  
ry ?2 o!  
/* @:&+wq_>A^  
**TestMethod.java O[y`'z;C  
*/ ?/( K7>`  
package NetFox; b-?o?}*  
Z?.*.<"Sj  
;ZJ,l)BNO  
public class TestMethod { X6,9D[Nw  
^wa9zs2s;/  
,NEs{! T  
public TestMethod() 3kCbD=yF  
{ ///xx/weblogic60b2_win.exe Y14R"*t~  
try{ {1aAm+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #!jRY!2Vt  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >!1f`  
SiteFileFetch fileFetch = new SiteFileFetch(bean); s8[9YfuW  
fileFetch.start(); 4C%>/*%8>  
} ^-u HdafP  
catch(Exception e){e.printStackTrace ();} w<Cmzkf  
rcx;3Vne  
S I7B6c  
} P|4E1O  
]$*{<  
UD2<!a'T  
public static void main(String[] args) +^? -}v  
{ 2g6_qsqi  
new TestMethod(); //lZmyP?  
} Iv72;ZCh?6  
} ]7kGHIJ|  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八