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http断点续传简单实现(java)

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/* HU'w[r 6a  
**SiteFileFetch.java D_?Tj  
*/ 8!0fT}  
package NetFox; u(FOSmNkN  
import java.io.*; &a4FGzR#  
import java.net.*; `-%dHvB^R  
 Cu5_OJ  
cpl Ny?UIC  
public class SiteFileFetch extends Thread { 2Y%7.YX"  
'%4fQ%ID}  
W**[:n+  
SiteInfoBean siteInfoBean = null; //文件信息Bean *+zFsu4l  
long[] nStartPos; //开始位置 w,X)g{^T  
long[] nEndPos; //结束位置 SHs [te[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Lc?"4  
long nFileLength; //文件长度 g%tUkM  
boolean bFirst = true; //是否第一次取文件 VQ,5&-9Y3  
boolean bStop = false; //停止标志 1TX3/]:  
File tmpFile; //文件下载的临时信息 tH&eKM4G  
DataOutputStream output; //输出到文件的输出流 tvf5b8(Y-  
?FNgJx*\S  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b1>]?.  
public SiteFileFetch(SiteInfoBean bean) throws IOException .rG~\Ws  
{ w_o+;B|I  
siteInfoBean = bean; bl&9O  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); hxj\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); &"W gO!pzD  
if(tmpFile.exists ()) >]anTF`d  
{ nBd]rak'  
bFirst = false; V dvj*I  
read_nPos();  ]Tb?z&  
} k~so+k&=b  
else ,tQN L\t  
{ :-#7j} R&  
nStartPos = new long[bean.getNSplitter()]; <{8x-zbR+  
nEndPos = new long[bean.getNSplitter()]; "=n%L +6%  
} nTc#I~\  
BKO^ux%  
cWyf04-?  
WMnSkO  
} 7D,nxx(`  
s-5 #P,Lw  
7FkiT  
public void run() BJ]L@L%  
{ q+4dHS)x  
//获得文件长度 p#Po?  
//分割文件 Q=d:Yz":S  
//实例FileSplitterFetch /s%-c!o^  
//启动FileSplitterFetch线程 )X," NJG  
//等待子线程返回 "=K3sk  
try{ V~#5^PF{  
if(bFirst) I$S*elveG  
{ Du +_dr^4  
nFileLength = getFileSize(); "=+i~N#Sc  
if(nFileLength == -1) WF*j^ %5  
{ ?$ov9U_  
System.err.println("File Length is not known!"); ~:k r;n2  
} )7!,_r  
else if(nFileLength == -2) TghT{h@  
{ <$hv{a  
System.err.println("File is not access!"); 0sA`})Dk  
} E+EcXf  
else l%('5oz@\  
{ \1&4wzT  
for(int i=0;i<nStartPos.length;i++) {>vgtkJ  
{ @aN~97 H\  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); F'>yBDm*OM  
} %).I &)i  
for(int i=0;i<nEndPos.length-1;i++) w0@XJH:P  
{ #g@4c3um|  
nEndPos = nStartPos[i+1]; ~3Pp}eO~V  
} <,it<$f#  
nEndPos[nEndPos.length-1] = nFileLength; >Ik%_:CC`  
} cUP1Uolvn  
} o\ce|Dzt  
.b`8 +  
7p\&D?  
//启动子线程 U[Sh){4j  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3?<A]"X.  
for(int i=0;i<nStartPos.length;i++) }6pr.-J  
{ h4itXJy52B  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5(\/ b<#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'AWWdz  
nStartPos,nEndPos,i); ]b>XN8y.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g18zo~LZ  
fileSplitterFetch.start(); Nxl#]  
} g~,iWoY  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =bP<cC=3b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,SIGfd  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |:4W5>sfg  
nEndPos = " + nFileLength); (pM& eow}  
// fileSplitterFetch[nPos.length-1].start(); ^fsC]9NS  
op2Zf?Bx{+  
kG9aH Ww  
//等待子线程结束 x!W5'DO  
//int count = 0; 0FH.=   
//是否结束while循环 js;YSg{m  
boolean breakWhile = false; Av yer/{  
K$GQc"  
|H,WFw1%}  
while(!bStop) zsd<0^ p\{  
{ ZybfqBTD&c  
write_nPos(); v5e*R8/  
Utility.sleep(500); TG8U=9qt  
breakWhile = true; of7p~{3H  
6&6dd_K(  
? p[Rv  
for(int i=0;i<nStartPos.length;i++) S76MY&Vx23  
{ YM NLn9  
if(!fileSplitterFetch.bDownOver) -Vb5d!(  
{ D-t!{LA  
breakWhile = false; 8 l= EL7  
break; yn@wce  
} @`nG &U  
} ^x/D8 M  
if(breakWhile) })kx#_o]'d  
break; MK! @ND  
C8qSoO4Z  
MQcIH2  
//count++; p/u  
//if(count>4) ek/zQM@%  
// siteStop(); lb*;Z7fx<'  
} \+/ciPzA-  
thX4-'i  
90Sras>F  
System.err.println("文件下载结束!"); bQ 0Ab"+D  
} sK9RViqF\  
catch(Exception e){e.printStackTrace ();} FqGMHM\J  
} )MTf  
yP} |8x  
_ MB/p  
//获得文件长度 ~,)D n  
public long getFileSize() x./"SQ=R+  
{ l O*  
int nFileLength = -1; /B 3\e3  
try{ -vc$I=b;  
URL url = new URL(siteInfoBean.getSSiteURL()); = \oW {?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9C Ki$L  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,JbP~2M~%  
m :~y:.  
c68y\  
int responseCode=httpConnection.getResponseCode(); |/8!P Km  
if(responseCode>=400) Btr>ek  
{ cD!E.2[  
processErrorCode(responseCode); c05-1  
return -2; //-2 represent access is error u0)9IZxc  
} vr?u=_%Z  
./.aLTh  
P|lDW|}D@  
String sHeader; O8v9tGZoh  
IZ^:wIKo{  
]B~ (yh  
for(int i=1;;i++) BG.8 q4[  
{ qe e_wx  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cH:&S=>h  
//Utility.log(in.readLine()); kz("LI]  
sHeader=httpConnection.getHeaderFieldKey(i); 'L9hM.+  
if(sHeader!=null) +eKLwM  
{ +R;LHRS%  
if(sHeader.equals("Content-Length")) Sd.Km a  
{ (~5]1S}F  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); umAO&S.+M  
break; 8cMX=P  
} <s|.2~  
} ci:|x =  
else |)0Ta 9~  
break; 2 w! 0$  
} 3,*A VcQA  
} PQYJn x}  
catch(IOException e){e.printStackTrace ();} WD[jEWMV7D  
catch(Exception e){e.printStackTrace ();} QuI!`/N)z  
|f1^&97=+  
ZWjje6  
Utility.log(nFileLength); SdMLO6-  
>\J<`  
7i02M~*uS  
return nFileLength; '^7UcgugB  
} '"LaaTTs  
&m9= q|;m  
BXxJra/V  
//保存下载信息(文件指针位置) vo)W ziHh  
private void write_nPos() (Nd)$Oq[4  
{ K)[\IJJM  
try{ " s_S!;w@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <HS{A$]  
output.writeInt(nStartPos.length); =`N 0  
for(int i=0;i<nStartPos.length;i++) mF4OLG3L0  
{ )$a6l8  
// output.writeLong(nPos); EKN<KnU%  
output.writeLong(fileSplitterFetch.nStartPos); K&gE4;>  
output.writeLong(fileSplitterFetch.nEndPos); T/%Y_.NtU  
} ,VUOsNN4\  
output.close(); ux6)K= ]  
} MU `!s b*  
catch(IOException e){e.printStackTrace ();} xdaq` ^Bbt  
catch(Exception e){e.printStackTrace ();} d|~'#:y@  
} @;{ZnRv14  
x{So  
'0_W< lGB  
//读取保存的下载信息(文件指针位置) $ rbr&TJ  
private void read_nPos() T?jN/}qg  
{ Eg2jexl  
try{ )S`Yl;oL  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hv:~)h$  
int nCount = input.readInt(); ^u0y<kItX  
nStartPos = new long[nCount]; 42,dHYdt  
nEndPos = new long[nCount]; u%1JdEWZd  
for(int i=0;i<nStartPos.length;i++) Yb[)ETf^  
{ pa?AKj]  
nStartPos = input.readLong(); 87)/dHc  
nEndPos = input.readLong(); 'iwTvkf{  
} Z?9G2<i  
input.close(); \)aFYDq#\  
} 3KkJQ5a  
catch(IOException e){e.printStackTrace ();} R `ob;>[Q  
catch(Exception e){e.printStackTrace ();} /S^>06{-+  
} ^HT vw~]5  
|m*l/@1  
>lek@euqw  
private void processErrorCode(int nErrorCode) $DnJ/hg;qD  
{ m@L>6;*  
System.err.println("Error Code : " + nErrorCode); *g:Dg I 2  
} WHLTJ]OB  
d#ab"&$bv  
)/OIzbA3#  
//停止文件下载 [{& OcEf  
public void siteStop() *] >R  
{ 8)Vl2z  
bStop = true; qAlX#]  
for(int i=0;i<nStartPos.length;i++) 3Y +;8ld  
fileSplitterFetch.splitterStop(); tF<&R& =  
YT)1_>*\  
Su +<mW  
} NQiu>Sg  
}  zNn  
//负责部分文件的抓取 ?LvU7  
**FileSplitterFetch.java [ {vX*q 3B  
*/ =W"T=p*j  
package NetFox; 30sA\TZ  
AxO.adQE%  
qzZ;{>_f  
import java.io.*; oGbh *  
import java.net.*; "dYT>w  
BPOT!-  
<@4V G  
public class FileSplitterFetch extends Thread { ).Iifu|ks  
%Br1b6 V  
{`> pigo  
String sURL; //File URL /%{CJ0Y  
long nStartPos; //File Snippet Start Position 0dD.xuor  
long nEndPos; //File Snippet End Position hX-^h2eV  
int nThreadID; //Thread's ID rCA0c8  
boolean bDownOver = false; //Downing is over ICG:4n(,  
boolean bStop = false; //Stop identical pk;S"cnk  
FileAccessI fileAccessI = null; //File Access interface GQjU="+  
m>!o Yy_  
:r:x|[3.  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C&EA@U5X^  
{ AnZy o a  
this.sURL = sURL; `J7@G]X;2  
this.nStartPos = nStart; KO[T&#y'  
this.nEndPos = nEnd; R.GDCGAL  
nThreadID = id; N];K  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p"*xye x  
} 8`I,KkWg   
*W 04$N  
mWLiXKnb  
public void run() M3JV^{O/DV  
{ `bLJ wJ7  
while(nStartPos < nEndPos && !bStop) l Yj$ 3  
{ AmCymT3P*e  
2@N-#x '  
Dj0D.}`~  
try{ 0juP"v$C>  
URL url = new URL(sURL); QV#HN"F/K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VjeF3pmBa  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3?!c<^"e  
String sProperty = "bytes="+nStartPos+"-"; ]&='E.f  
httpConnection.setRequestProperty("RANGE",sProperty); 5pff}Ru`  
Utility.log(sProperty); jF#Dc[*  
d@Wze[M?0  
eG.s|0`  
InputStream input = httpConnection.getInputStream(); "412w^5[T  
//logResponseHead(httpConnection); Tg=P*HY6  
 Tx'anP  
4:s,e<Tc4v  
byte[] b = new byte[1024]; l @E {K|  
int nRead; fP\*5|7%R  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -BwZ  
{ ,~Lx7 5{  
nStartPos += fileAccessI.write(b,0,nRead); (H]NL   
//if(nThreadID == 1) A9GSeW<  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :j32 :/u  
} 'Awd:Aed5  
4P7r\ hs  
X&M04  
Utility.log("Thread " + nThreadID + " is over!"); =66'33l2  
bDownOver = true; n6 c+Okj  
//nPos = fileAccessI.write (b,0,nRead); Z:,`hW*A6  
} }+)q/]%  
catch(Exception e){e.printStackTrace ();} h=kC3ot\  
} 4`+R |"4  
} =&: |a$C  
uj)fah?Wg  
idjk uB(6  
//打印回应的头信息 $L'[_J  
public void logResponseHead(HttpURLConnection con) F$YT4414  
{ # 3FsK  
for(int i=1;;i++) sP>-k7K.  
{ ~svea>Fmr  
String header=con.getHeaderFieldKey(i); ?ihRt+eR~  
if(header!=null) fUq #mkq}  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h5v=h>c  
Utility.log(header+" : "+con.getHeaderField(header)); fM(~>(q&  
else "|E'E"_1  
break; @F|pKf:M+  
} -AB0uMot  
} m`tX&K#-  
2=VFUR 8  
r\C"Fx^  
public void splitterStop() ey n-bw  
{ Fg i;%  
bStop = true; !R[~Z7b6  
} @"aqnj>+  
(De>k8  
3/,}&SX  
} `2M*?.vk  
}:]CXrdg>  
EO/41O  
/* #9HX"<5  
**FileAccess.java M>{*PHze0  
*//文件访问(定位,写) K d{o/R  
package NetFox; NjO_Y t  
import java.io.*; 7gRR/&ZK  
P9jSLM  
zu,Yuq  
public class FileAccessI implements Serializable{ l4& l)4Rx  
.OlPVMFt  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  1%";|  
RandomAccessFile oSavedFile; )E^Pn|H  
long nPos; p?4,YV|#  
`r %lB  
q7I(x_y /  
public FileAccessI() throws IOException [<wpH0lNoy  
{ qu;$I'Ul%  
this("",0); \0FwxsL  
} #[Rs&$vQm  
jcRe),  
R_ )PbFw  
public FileAccessI(String sName,long nPos) throws IOException +DE;aGQ.z?  
{ 1aPFpo!  
oSavedFile = new RandomAccessFile(sName,"rw"); 4rpry@1  
this.nPos = nPos; n8i: /ypB  
oSavedFile.seek(nPos); tY#Zl 54~{  
} XI,=W  
hd`jf97*  
dt/-0~U  
public synchronized int write(byte[] b,int nStart,int nLen) i\x@s>@x}  
{ l9 &L$,=  
int n = -1; 4P#4R B  
try{ uI I! ?   
oSavedFile.write(b,nStart,nLen); ^4et; F%  
n = nLen; PO ,zP9  
} zT93Sb  
catch(IOException e) ;Nd'GA+1;(  
{ d<w]>T5VW  
e.printStackTrace (); ^ ~dC&!D  
} e{^^u$C1.e  
(i1p6  
pwV~[+SS_  
return n; KDj/S-S  
} Z/ L%?zH  
;J:*r0  
TV`sqKW  
} mE &SAm5#d  
+Eel|)Z*Q  
G2b"R{i/,  
/*  i(V  
**SiteInfoBean.java !/X>k{  
*/ \S{ihS@J  
package NetFox; {Z178sik  
uuL(BUGt-  
a %?v/Ku  
public class SiteInfoBean { q d:"LS  
4JXJ0T ar  
z 0F55<i  
private String sSiteURL; //Site's URL nswhYSX  
private String sFilePath; //Saved File's Path Bj\Us$cZ  
private String sFileName; //Saved File's Name b`f6(6  
private int nSplitter; //Count of Splited Downloading File 2-@t,T  
;Zn&Nc7  
7p>T6jK)  
public SiteInfoBean() D[4%CQ1m  
{//nSplitter的缺省值为5 c5pK%I}O  
//default value of nSplitter is 5 K cW 5  
this("","","",5); Dj6^|R$z&  
} ]cMZ7V^  
==trl#kQ%%  
*z0 R f;  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %/ :&L+q  
{ ^ (J%)&_\3  
sSiteURL= sURL; _,I~1"  
sFilePath = sPath; o@C|*TXN  
sFileName = sName; u#Bj#y!  
this.nSplitter = nSpiltter; g4;|uK;  
f lt'~fe  
4ywtE}mp  
} dP#7ev]'  
gADqIPu]  
ad=7FhnIa3  
public String getSSiteURL() =`Ky N/  
{ =F dFLrx~l  
return sSiteURL; 17w{hK4o8O  
} 1&Ma`M('  
UWdqcOr  
 UF@.  
public void setSSiteURL(String value) :`0,f?cE  
{ A5[kYD,_  
sSiteURL = value; A{\DzUV9,  
} $"#M:V @  
L3j ~Ooo  
?DnQU"_$  
public String getSFilePath() >xH?`I7;f  
{ D7c+/H@PF  
return sFilePath; 7 Rc/<,X  
} -x?|[ +%  
RusiCo!r  
Oo ^ AE  
public void setSFilePath(String value) dkg+_V!  
{ 5bol)Z9BO  
sFilePath = value; `}8)P#  
} PAVlZ}kj  
#;m^DX QZn  
49Y:}<Yd   
public String getSFileName() psS^  
{ 'z+Pa^)v  
return sFileName; UA#=K+2  
} ]HRHF'4  
")fgQ3XZ  
7'`nTF-@v  
public void setSFileName(String value) 472'P  
{ TETfRnm  
sFileName = value; P+3 ]g{2w  
} ]0{,P !  
#!rH}A>n+  
.0|_J|{  
public int getNSplitter() q"-Vh,8h  
{ "{jVsih0  
return nSplitter; `"$9L[>  
} A~L Ti  
T{BGg  
s2nZW pIy  
public void setNSplitter(int nCount) CKDg3p';  
{ q"LT8nD\  
nSplitter = nCount; gX* &RsF  
} g~OG~g@  
} q?f-h<yRQ  
@*$"6!3s5  
J/[PA[Rf  
/* UG<<.1JL  
**Utility.java t4-0mNBZt$  
*/ 2$gFiZ  
package NetFox; pFwe&_u]  
?W&ajH_T  
6p 14BruV  
public class Utility { \/r]Ra  
i2\CDYP  
(. ,{x)H  
public Utility() `oE.$~'  
{ fl*49-d  
Ba n^wX  
N/E=-&E8  
} ]oC7{OoX  
'qidorT>N  
//线程睡眠 f{'N O`G  
public static void sleep(int nSecond) JJP!9<  
{ ?;go5f+X  
try{ h0VeXUM;.  
Thread.sleep(nSecond); sWgzHj(c  
} 1mx;b)4t  
catch(Exception e) @9MrTP  
{ EFs\zWF  
e.printStackTrace (); a & 6-QVk  
} j!a&l  
} dp:5iuS  
{|Fn<&G  
//日志  V#+J4   
public static void log(String sMsg) K*"Fpx{M  
{ L!2Ef4,wAz  
System.err.println(sMsg); 0#F<JsO|u  
} "04:1J`  
Aac7k m  
x2g=%K=  
public static void log(int sMsg) NbUibxJ  
{ eZ(o_  
System.err.println(sMsg); kwFo*1 {  
} |%=c<z+8  
} m9aP]I3g]\  
.r-kH&)"GU  
v/3Vsd  
/* U[!wu]HMF  
**TestMethod.java Zg >!5{T  
*/ g^:7mG6C  
package NetFox; Zor Q2>  
!(N,tZ  
!]!9 $6n  
public class TestMethod { 4rNuAK`2  
HOVzpj  
]@sLX ek  
public TestMethod() &>hln<a>  
{ ///xx/weblogic60b2_win.exe `mKK1x  
try{ 8#a2 kR<b  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ybgw#jv=  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m pM,&7}  
SiteFileFetch fileFetch = new SiteFileFetch(bean); NW?h~2  
fileFetch.start(); XN'<H(G  
} Fi#b0S  
catch(Exception e){e.printStackTrace ();} 6x! q  
q.p.y0  
,j\UZ  
} UC"_#!3  
{s[,CUL0  
h/#s\>)T  
public static void main(String[] args) P Z+Rz1x  
{ *lp{,  
new TestMethod(); ~g;lVj,N'  
} ]N1gzHaS  
} u[coWaPsZ  
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