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
  • 11593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
/* )9^)t   
**SiteFileFetch.java SIapY%)h  
*/ f"RC(("6W  
package NetFox; yX4 Vv{g  
import java.io.*; 58XZ]Mc0  
import java.net.*; " i:[|7  
q>Di|5<y  
3m= _a  
public class SiteFileFetch extends Thread { l]4=W<N  
$33E-^  
 $TfB72  
SiteInfoBean siteInfoBean = null; //文件信息Bean Da615d  
long[] nStartPos; //开始位置 &#L C'  
long[] nEndPos; //结束位置 (>vyWd]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 O 2-n-  
long nFileLength; //文件长度 6#7hMQ0&;O  
boolean bFirst = true; //是否第一次取文件 H1f='k]SZ  
boolean bStop = false; //停止标志 w i[9RD@  
File tmpFile; //文件下载的临时信息 i,h30J  
DataOutputStream output; //输出到文件的输出流 ULqI]k(  
 4d\^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) eT+i &  
public SiteFileFetch(SiteInfoBean bean) throws IOException +N=HI1^54R  
{ "]#Ij6ml  
siteInfoBean = bean; t5%cpkgh4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <4+P37^ ~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Ie(i1?`A8  
if(tmpFile.exists ()) &nDXn|  
{ ]f#s`.A~  
bFirst = false; L/ Q[N^ (^  
read_nPos(); o!:Z?.!  
} 1l$2T y+ =  
else (IBT|K  
{ XjF@kQeM=  
nStartPos = new long[bean.getNSplitter()]; j1KNgAo<4  
nEndPos = new long[bean.getNSplitter()]; =B9-}]DDO  
} 5]>*0#C S  
 +=jS!  
Bhxs(NO  
yI 2UmhA  
} 3l%Qd<  
5afD;0D5TI  
R|n  
public void run() Xd=KBB[r?  
{ gzIx!sc  
//获得文件长度 [02rs@c>  
//分割文件 tGgxID  
//实例FileSplitterFetch <Cv(@A->  
//启动FileSplitterFetch线程 [K&%l]P7  
//等待子线程返回 [ N|X  
try{ !{g<RS( c  
if(bFirst) rz@q W2  
{ &J)<1!|  
nFileLength = getFileSize(); _;B wP  
if(nFileLength == -1) 1(-!TJ{  
{ pASX-rb  
System.err.println("File Length is not known!"); 9a=Ll]=\  
} !\X9$4po@  
else if(nFileLength == -2) (da`aRVDp  
{ =SXdO)%2  
System.err.println("File is not access!"); F%h3?"s  
} . :Skc  
else j:h}ka/!p  
{ sq!$+=1-X  
for(int i=0;i<nStartPos.length;i++) mY.v:  
{ 1Z) Et,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8cG?p  
} @ j^R+F  
for(int i=0;i<nEndPos.length-1;i++) Z1eT> 6|]r  
{ rZKfb}ANQ  
nEndPos = nStartPos[i+1]; wAKHD*M)  
} f`n4'dG  
nEndPos[nEndPos.length-1] = nFileLength; Z^_qXerjP  
} !?nbB2,  
} hyH[`wiq  
ysz =Xw  
_K o#36.S  
//启动子线程 V4+ |D2   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .\ ;'>qy  
for(int i=0;i<nStartPos.length;i++) ECOJ .^  
{ h^SWb9 1"G  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `gX|q3K\s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D5,]E`jwu  
nStartPos,nEndPos,i); oZa'cZNs  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'OsZD?W{  
fileSplitterFetch.start(); 8M99cx*K  
} wM+1/[7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4.!1odKp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); } ?j5V  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B?! L~J@p  
nEndPos = " + nFileLength); 6Ijt2c'A}  
// fileSplitterFetch[nPos.length-1].start(); t3@+idEb  
ISGw}#}]?  
J!2Z9<q5  
//等待子线程结束 ^ Oh  
//int count = 0; k7^hc th  
//是否结束while循环 *%Rmdyn  
boolean breakWhile = false; 4j#y?^s  
(xHmucmwp  
J].Oxch&y  
while(!bStop) d=D-s  
{  k,:W]KD  
write_nPos(); =Kd'(ct  
Utility.sleep(500); +<a\0FsD  
breakWhile = true; jE*{^+n  
7*l$ i/!  
z`zz8hK.  
for(int i=0;i<nStartPos.length;i++) geme_  
{ eFG/!b<17  
if(!fileSplitterFetch.bDownOver) 3`bQ0-D;  
{ ;P91'B~t  
breakWhile = false; {7o3wxsS  
break; 6KMO*v  
} ,<v0(  
} wZ(1\ M(  
if(breakWhile) fz(YP=@ZnP  
break; #EH=tJgO|J  
BU:;;iV8  
=W~7fs  
//count++; ON,[!pc  
//if(count>4) i#'K7XM2  
// siteStop(); qYK^S4L  
} MgXZN{  
Tn&_ >R  
#`VAw ) eV  
System.err.println("文件下载结束!"); ;z'&$#pA  
} 8ymdg\I+L  
catch(Exception e){e.printStackTrace ();} BJjic%V  
} ,"EaZ/Bl/  
2lTt  
}J#HIE\RG  
//获得文件长度 *ERV\/  
public long getFileSize() "^#O7.oVi+  
{ zjmo IE  
int nFileLength = -1; P~j#8cH7  
try{ Bgxk>Y  
URL url = new URL(siteInfoBean.getSSiteURL()); S2$66xr#  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {KG}m'lx  
httpConnection.setRequestProperty("User-Agent","NetFox"); +F)EGB%LXs  
GW A T0  
Ui'v ' $  
int responseCode=httpConnection.getResponseCode(); t]h_w7!U  
if(responseCode>=400) 2 R\K!e  
{ 5i[O\@]5  
processErrorCode(responseCode); &W45.2  
return -2; //-2 represent access is error p:~#(/GWf  
} ~ P\4 N  
%Psg53N  
~su>RolaX  
String sHeader;  ?(9*@  
=t,oj6P~  
hIV9.{J  
for(int i=1;;i++) [U&k"s?  
{ _}F& ^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y!b"Cj  
//Utility.log(in.readLine()); @NM0ILE  
sHeader=httpConnection.getHeaderFieldKey(i); B ~v6_x  
if(sHeader!=null) "yu{b]AU  
{ A[l )>:  
if(sHeader.equals("Content-Length"))  "9;  
{ 2+&;jgBP  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x{pj`'J)  
break; TAYh#T=S  
} [j6]!p]S$  
} V D#q\  
else sl$6Zv-l%0  
break; ^(q .f=I!a  
} QD-\'Bp/X  
} Vh0cac|X  
catch(IOException e){e.printStackTrace ();} 7m#EqF$P  
catch(Exception e){e.printStackTrace ();} E-WpsNJ)X  
lf=G  
EB3/o7)L  
Utility.log(nFileLength); f&vMv.  
!KI^Z1dP(  
Fg`<uW]TFZ  
return nFileLength; p*<Jg l  
} /we]i1-9  
-53c0g@X  
=X'[r  
//保存下载信息(文件指针位置) ~i1 jh:,  
private void write_nPos() #ft9ms#N  
{ Qb {[xmc  
try{ G8}owszT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); - +a,Ej  
output.writeInt(nStartPos.length); iQO4IT   
for(int i=0;i<nStartPos.length;i++) LVUA"'6V  
{ `+Nv =vk  
// output.writeLong(nPos); vd%AV(]<LJ  
output.writeLong(fileSplitterFetch.nStartPos); "nz\YQdg  
output.writeLong(fileSplitterFetch.nEndPos); 2*sTU  
} &<><4MQ  
output.close(); M[qhy.  
} ?b7ttlX{  
catch(IOException e){e.printStackTrace ();} {J"]tx9 ]  
catch(Exception e){e.printStackTrace ();} 2D:/.9= 8v  
} _OGv2r  
y{M7kYWtHV  
r 1HG$^  
//读取保存的下载信息(文件指针位置) Kb ]}p  
private void read_nPos() ,~3rY,y-  
{ ^P,Pj z  
try{ S/oD`   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XVN JK-B  
int nCount = input.readInt(); 3/gR}\=  
nStartPos = new long[nCount]; +X#6 d v$  
nEndPos = new long[nCount]; m ^FKE:  
for(int i=0;i<nStartPos.length;i++) ?n# $y@U  
{ ?$`kT..j,u  
nStartPos = input.readLong(); \dQc!)&C9  
nEndPos = input.readLong(); Yz;7g8HI  
} 3D6&0xTq  
input.close(); B*:I-5  
} 0:Bpvl5  
catch(IOException e){e.printStackTrace ();} %<^^ Mw  
catch(Exception e){e.printStackTrace ();} bGwOhd<.  
} |[~ S&  
zHKP$k8  
C[fefV9g2  
private void processErrorCode(int nErrorCode) ^U?Ac=  
{ g(zeOS]q}  
System.err.println("Error Code : " + nErrorCode); yf*'=q  
} RR=WD-l  
-\p&18K#  
Fa h6 &a  
//停止文件下载 V]Te_ >E;w  
public void siteStop() J#Q>dC7  
{ :^W}$7$T  
bStop = true; <cZ/_+H%C  
for(int i=0;i<nStartPos.length;i++) >&\.{ aj  
fileSplitterFetch.splitterStop(); }bRn&)e  
I Tl>HlS  
p9jC-&:  
} (Q*x"G#4>  
} V0D&bN*  
//负责部分文件的抓取 8Vz!zYl  
**FileSplitterFetch.java @_t=0Rc  
*/ FI:H/e5[  
package NetFox; Zrwd  
jvv=  
wdt2T8`I/  
import java.io.*; ?#a&eW  
import java.net.*; Jqzw94  
2ih}?%H8  
Syseiw  
public class FileSplitterFetch extends Thread { _8r'R  
q{V e%8$"  
/t`|3Mw  
String sURL; //File URL e<uf)K=(C  
long nStartPos; //File Snippet Start Position 0,-]O=   
long nEndPos; //File Snippet End Position X9PbU1o;  
int nThreadID; //Thread's ID @-K[@e/uwy  
boolean bDownOver = false; //Downing is over ;07$G+['  
boolean bStop = false; //Stop identical Xl1%c7r.1  
FileAccessI fileAccessI = null; //File Access interface kI a16m  
9:g A0Z  
_1RvK? ;.{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4<tbZP3/6)  
{ B#hvw'}  
this.sURL = sURL; :LB*l5\  
this.nStartPos = nStart; ~)#E?:h5  
this.nEndPos = nEnd; LK4NNZf7  
nThreadID = id; ">!pos`<C  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uO]|YF  
} vn*K\,  
J|hVD  
`3jwjy| 5  
public void run() I++ Le%w  
{ .Y2Hd$rs  
while(nStartPos < nEndPos && !bStop) NRG06M  
{ q_ ^yma  
P7T'.|d  
f99"~)B|  
try{ ez9F!1  
URL url = new URL(sURL); Py #EjF12  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #-Mr3  
httpConnection.setRequestProperty("User-Agent","NetFox"); Wm"q8-<<  
String sProperty = "bytes="+nStartPos+"-"; 8.jf6   
httpConnection.setRequestProperty("RANGE",sProperty); [(g2u@  
Utility.log(sProperty); 1`|Z8Jpocj  
zOA~<fhT  
J~J+CGT~2  
InputStream input = httpConnection.getInputStream(); P<Z` 8a[  
//logResponseHead(httpConnection); &ZMQ]'&  
|wJdp,q R  
$bp$[fX(e  
byte[] b = new byte[1024]; sqpo5~  
int nRead; ";`jS&"=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \IC^z  
{ &Jb$YKt  
nStartPos += fileAccessI.write(b,0,nRead); IhK SwT  
//if(nThreadID == 1) h}'Hst  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q=%W-  
} $bKXP(  
E@otV6Wk[@  
{S+?n[1r\  
Utility.log("Thread " + nThreadID + " is over!"); D=vw0Q_3Y3  
bDownOver = true; #b&tNZ4!_  
//nPos = fileAccessI.write (b,0,nRead); pam9wfP  
}  |15!D  
catch(Exception e){e.printStackTrace ();} iku*\,6W  
} Gjq7@F'  
} 2o9B >f&g  
'_7rooU9  
'Q=)-  
//打印回应的头信息 8EkzSe  
public void logResponseHead(HttpURLConnection con) P@GU2[1  
{ l]D $QT3  
for(int i=1;;i++) 'bLP#TAzf  
{ ( ./MFf  
String header=con.getHeaderFieldKey(i); f?^-JZ  
if(header!=null) dZIbajs'  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r?Mf3U^G  
Utility.log(header+" : "+con.getHeaderField(header)); \z2y?"\?  
else I+twI&GS  
break; LHx ")H?,  
} 2!}F+^8'P  
} 3 eF c  
@=AQr4&  
YCStX)r  
public void splitterStop() GPGP teC  
{ H-&27?s^  
bStop = true; T<>B5G~%  
} *7Y#G8 s  
"8uNa  
p*g)-/mA  
} un!v1g9O  
l i?@BHEf  
+ \%]<YO  
/* ox<&T|  
**FileAccess.java 2G-"HOG  
*//文件访问(定位,写) VHqoa>U,*  
package NetFox; 7neJV  
import java.io.*; ct|0zl~  
{*n<A{$[ m  
4qE4 i:b  
public class FileAccessI implements Serializable{ $ S3b<]B  
A p?,y?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y)lr+~84f  
RandomAccessFile oSavedFile; ><IWF#kUA  
long nPos; G Wa6FX:/  
ipMSMk7gx  
/d6Rd l`w  
public FileAccessI() throws IOException mE{QTZS  
{ ;u(*&vRqr^  
this("",0); T ?[;ej:  
} vOCaru?~h  
s&o9LdL  
I:oEt  
public FileAccessI(String sName,long nPos) throws IOException Ebj0 {ZL  
{ W3Ee3  
oSavedFile = new RandomAccessFile(sName,"rw"); S9$,.aq  
this.nPos = nPos; 3)CIqN  
oSavedFile.seek(nPos); ayn aV  
} i" u|119  
i Pr(X  
VfJ{);   
public synchronized int write(byte[] b,int nStart,int nLen) A9SL|9Q  
{ oI`Mn3N  
int n = -1; 1;kMbl]  
try{ 8;"%x|iBoL  
oSavedFile.write(b,nStart,nLen); UMNNAX  
n = nLen; |Fze9kZO  
} 3}phg  
catch(IOException e) ns5Dydo{T  
{ .eVX/6,  
e.printStackTrace (); gn/]1NNfR  
} O^./) #!#  
6W3oIt  
]Oo!>iTQi  
return n; :epB:r  
} p`7d9MV^  
]<YS7.pT  
mYJ8O$  
} uMG y-c  
I*o6Bn |D  
H'k~;  
/* Jpp-3i.F#  
**SiteInfoBean.java '>1M~B  
*/ _(gkYJ+MK  
package NetFox; # SCLU9-  
&,PA+#  
Z>3~n  
public class SiteInfoBean { bxxLAWQ(  
\6APU7S  
B[YyA  
private String sSiteURL; //Site's URL 5M'cOJ  
private String sFilePath; //Saved File's Path 9cN@y<_I  
private String sFileName; //Saved File's Name $4ZV(j]  
private int nSplitter; //Count of Splited Downloading File * Uy>F[%@  
,3}+t6O"  
a9^})By&  
public SiteInfoBean() kzUj)  
{//nSplitter的缺省值为5 Oz_CEMcy  
//default value of nSplitter is 5 3;}YW^oXq  
this("","","",5); RaTNA W)v>  
} NW0se DL  
3"0QW4A  
b0h\l#6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KgD$P(J:[  
{ H*0g*(  
sSiteURL= sURL; jZidT9[g  
sFilePath = sPath; @%u}|iF|  
sFileName = sName; B[8 RBTsA  
this.nSplitter = nSpiltter; AriV4 +  
_O87[F1  
]x8Y]wAU&{  
} +U,t*U4,  
] X]!xvN@  
B&59c*K  
public String getSSiteURL() Z \ @9*  
{ 0]DX KI  
return sSiteURL; x2I|iA=  
} LHOt(5VY  
kn3GgdU  
6-?/kY6  
public void setSSiteURL(String value) n@bkZ/G  
{ +J|LfXgB  
sSiteURL = value; tZ@&di:-F  
} !(Y|Vm'   
MMaS  
p\'X%R  
public String getSFilePath() ~PF,[$?4n  
{ k"BM1-f  
return sFilePath; Edh9=sxL  
} u\xrC\Ka  
G5 )"%G.  
u|ihUE!h  
public void setSFilePath(String value) p'@z}T?F  
{ Gk58VODo  
sFilePath = value; loq2+(  
} &2@Rc?!6_P  
!m_y@~pV#u  
wp~KrUlR  
public String getSFileName() T72Z<h|<  
{ Avljrds+7  
return sFileName; u5U^}<}y}  
} d@Bd*iI<  
\Z%_dT}  
}Sh@.3*  
public void setSFileName(String value) sKiy 1Ww  
{ 1#>uqUxah  
sFileName = value; 8BS Nm  
} w[QC  
Zmk 9C@  
<Z]j89wzDZ  
public int getNSplitter() E){ODyk  
{ (]fbCH:  
return nSplitter; 8rU| Oh  
} UY.o,I> s  
|P9)*~\5  
@frV:%  
public void setNSplitter(int nCount) Opy{i#>  
{ 5PpS/I:on  
nSplitter = nCount; M M @&QaK  
} rO1N@kd/  
} DYZk1  
65+2+p  
XL1x8IB  
/* vHPsHy7y  
**Utility.java $Zrc-tkV  
*/ 3ox|Mz<aZX  
package NetFox; /b4>0DXT5  
uAk>VPuuZ  
1F2(MKOo!  
public class Utility { e5n"(s"G*[  
vsq |m 5  
?FZ) LZM  
public Utility() C6tfFS3bq  
{ vhU $GG8  
&y3;`A7,  
_(@V f=t  
} xWWVU}fd1  
Ci3 b(KR  
//线程睡眠 [RDY(}P%  
public static void sleep(int nSecond) sa"!ckh  
{  `7V'A  
try{ 7<5=fYb r  
Thread.sleep(nSecond); r8_MIGM'  
} P$/Y9o  
catch(Exception e) (. $e@k=  
{ cm>+f^4?n  
e.printStackTrace (); Qz<i{r-z  
} jq/CXYv  
} JWxSN9.X  
ae+*gkPv8  
//日志 Oj7).U0;#  
public static void log(String sMsg) 5*y6{7FLp  
{ Qer}eg`R  
System.err.println(sMsg); GRgpy  
} v@:m8Y(t  
5lE9UoG[Q  
pf&SIG  
public static void log(int sMsg) xwijCFI*  
{ "(;t`,F  
System.err.println(sMsg); ;Z&w"oSJ  
} j|r$ ! gV  
} )EsFy6K:  
"!o|^nN,  
S"Ag7i  
/* n1y*`5!  
**TestMethod.java  1W>0  
*/ R+=Xr<`%U|  
package NetFox; l27J  
A^7}:[s20  
}pT>dbZ  
public class TestMethod { HwBJUr91]  
#\O?|bN'q  
t)l^$j !h@  
public TestMethod() @p9YHLxLjQ  
{ ///xx/weblogic60b2_win.exe %wmbFj}  
try{ G>+iisb%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{Gf@  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r 4+%9)  
SiteFileFetch fileFetch = new SiteFileFetch(bean); J/A UOInh  
fileFetch.start();  BbNl:`  
} 2,'%G\QT  
catch(Exception e){e.printStackTrace ();} (0 S;eM&  
{mB &xz:b  
J<ZG&m362p  
} 24d{ol)  
{pk&dB _Bu  
$7&t`E)qY  
public static void main(String[] args) l|  QQ  
{ E"t79dD  
new TestMethod(); >L88`  
} 8F T@TUFb  
} A@ 4Oq  
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
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八