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http断点续传简单实现(java)

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/* efy65+~GG  
**SiteFileFetch.java Ha@'%<gFe  
*/ 4v33{sp  
package NetFox; wxkCmrV  
import java.io.*;  nk>  
import java.net.*; 3DV';  
.|JJyjRA+  
v98=#k!F  
public class SiteFileFetch extends Thread {  Mhm3u  
}\:3}'S.$  
xKWqDt  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2xhwi.u  
long[] nStartPos; //开始位置 Sf B+;i'D  
long[] nEndPos; //结束位置 Yew n  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 cNtGjLpx;  
long nFileLength; //文件长度 [pUw(KV2m  
boolean bFirst = true; //是否第一次取文件 wV+ W(  
boolean bStop = false; //停止标志 D!h8NZ;El  
File tmpFile; //文件下载的临时信息 B&Q\J>l9S  
DataOutputStream output; //输出到文件的输出流 !lKO|Y  
+J} wYind  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $\Bzp<SN`  
public SiteFileFetch(SiteInfoBean bean) throws IOException K19/M1~  
{ h8Q+fHDYv  
siteInfoBean = bean; X]U,`oE)9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Qg"hN  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); hF s:9  
if(tmpFile.exists ()) 01g=Cg  
{ >N@tInE  
bFirst = false; {UX?z?0T  
read_nPos(); /1F%w8Iqh  
} %I9{)'+@x  
else X|q&0W=  
{ rIH/<@+  
nStartPos = new long[bean.getNSplitter()]; u pg?  
nEndPos = new long[bean.getNSplitter()];  U":hJ*F)  
} l~;H~h!h/  
t 9&xk?%{  
((Ak/qz  
;&q}G1  
} I@+h| n  
j2c -01}  
S_/9eI~X  
public void run() <`i " 5`J  
{ 15+>W4v  
//获得文件长度 |!E>I  
//分割文件 dqnH7okZ  
//实例FileSplitterFetch y  >r7(qg  
//启动FileSplitterFetch线程 n$ $^(-g@)  
//等待子线程返回 lqn7$  
try{ B8UtD  
if(bFirst) veAg?N<c p  
{ C8rD54A'M  
nFileLength = getFileSize(); I|9(*tq)  
if(nFileLength == -1) HS XS%v/Y  
{ f]`#BE)V  
System.err.println("File Length is not known!");  n0F.Um  
} FRd!UqMXY  
else if(nFileLength == -2) (+6 8s9XS7  
{ C93BK)$}  
System.err.println("File is not access!"); Xf!@uS6<X  
} NUbw]Y90~  
else u~[HC)4(0  
{ fuSfBtLPR#  
for(int i=0;i<nStartPos.length;i++) ^e:C{]S=  
{ +%Q:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,A`d!{]5  
} 0{^vqh.La  
for(int i=0;i<nEndPos.length-1;i++) 1 rKKph  
{ 6E/>]3~!  
nEndPos = nStartPos[i+1]; Se<]g$eK?5  
} "[2CV!_  
nEndPos[nEndPos.length-1] = nFileLength; l*>t@:2J  
} $3<,"&;Ecs  
} 6w(Mb~[n  
+KgoLa  
v,y nz'>)  
//启动子线程 2+zE|I.  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^!^6 |[  
for(int i=0;i<nStartPos.length;i++) BZq_om6  
{ 0T7(c-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! Ob  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %a=K:" oU[  
nStartPos,nEndPos,i); >}Qj|05G  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  Ec IgX_\  
fileSplitterFetch.start(); 9pUvw_9MY  
} fZ1v|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :f%FM&b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D X GClH  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VN[C%C  
nEndPos = " + nFileLength); 59mNb:<  
// fileSplitterFetch[nPos.length-1].start(); <6QG7 i  
uMVM-(g%  
%|E'cdvkX  
//等待子线程结束 _Z?{&k  
//int count = 0; @)PA9P |  
//是否结束while循环 mAMi-9  
boolean breakWhile = false; **_`AM~  
D,q=?~  
g?` g+:nug  
while(!bStop) .w2QiJ  
{ Go~bQ2*'(/  
write_nPos(); BC*vG=a  
Utility.sleep(500); _nu,ks+  
breakWhile = true; Tlrr02>B{  
IN=pki |.  
^,u0kMG5l  
for(int i=0;i<nStartPos.length;i++) |T?wM/  
{ sqTBlP  
if(!fileSplitterFetch.bDownOver) Ay)q %:qx  
{ :K.%^ag=j  
breakWhile = false;  R}Pw#*B  
break; io :g ]g  
} QK _1!t3  
} 88}+.-3t$  
if(breakWhile)  7'u<)V  
break; dv=y,q@W  
%pj 6[x`@  
PN9^ sLx=  
//count++; r@N 0%JZZ  
//if(count>4) j !^Tw.Ty  
// siteStop(); {Hncm  
}  :VwU2  
x g=}MoX  
2VmQ%y6e"  
System.err.println("文件下载结束!"); =B4,H=7Spf  
} HUqG)t*c1  
catch(Exception e){e.printStackTrace ();} Oop5bg  
} VD}8ei  
jv $Y]nf  
RtVy^~=G  
//获得文件长度 '=MaO@ @  
public long getFileSize() fxfzi{}uj  
{ r @C2zF7  
int nFileLength = -1; P^m+SAAB  
try{ z'@j9vT  
URL url = new URL(siteInfoBean.getSSiteURL()); n8<o*f&&9>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dFY]~_P472  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3TUW+#[Gu  
] jbQou@  
GMmz`O XN  
int responseCode=httpConnection.getResponseCode(); 9$,x^Qx  
if(responseCode>=400) $r`K4g  
{ h(}$-'g  
processErrorCode(responseCode); dWHl<BUm  
return -2; //-2 represent access is error v|5:;,I  
} is=sV:j:  
+mRFHZG  
/H#- \r&r  
String sHeader;  2|'v[  
a*LT<N  
YnnpgR.  
for(int i=1;;i++) gcYx-gA}  
{ >! +.M9  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xlPUu m-o  
//Utility.log(in.readLine()); TDI8L\rr  
sHeader=httpConnection.getHeaderFieldKey(i); wMy$T<:   
if(sHeader!=null) m"Y;GzqQl  
{ ~3}Gu^@  
if(sHeader.equals("Content-Length")) e$F]t *)Xa  
{ z;1y7W!v  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %bI(   
break; |8I #`  
} 8r '  
} .DSn H6O  
else (IX iwu  
break; ^l1tQnj)7  
} =H*}{'#  
} shW$V93<  
catch(IOException e){e.printStackTrace ();} U3r[ysf  
catch(Exception e){e.printStackTrace ();} ( Lj{V}^  
\)'nxFKqV  
`|K,E  
Utility.log(nFileLength); b?Wg|D  
3L/qU^`  
=a rk?<E  
return nFileLength; %M8Egr2|0  
} "8K>Yu17  
R'a%_sACj>  
H <CsB  
//保存下载信息(文件指针位置) ,4y' (DA  
private void write_nPos() N;,?k.vU  
{ 97:1L4w.(  
try{ .0]4@'  
output = new DataOutputStream(new FileOutputStream(tmpFile)); wUzQ`h2  
output.writeInt(nStartPos.length); Hj ]$  
for(int i=0;i<nStartPos.length;i++) PoMkFG6  
{ /x.TF'Z*  
// output.writeLong(nPos); Q,Tet&in )  
output.writeLong(fileSplitterFetch.nStartPos); ]2G5ng' @  
output.writeLong(fileSplitterFetch.nEndPos); <%eY>E  
} >}QRMn|@H  
output.close(); w?CbATQ   
} 0P`wh=")  
catch(IOException e){e.printStackTrace ();} `mPmEV<  
catch(Exception e){e.printStackTrace ();} f@l6]z{.L  
} ~ZU;0#  
C("PCD   
A7U'>r_.  
//读取保存的下载信息(文件指针位置) CG'NC\x5  
private void read_nPos() R`=3lY;  
{ &SS"A*xg  
try{ Lm+!/e  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ) Kfk\  
int nCount = input.readInt(); '$Jt}O  
nStartPos = new long[nCount]; eydVWVN  
nEndPos = new long[nCount]; ln.kEhQ3B  
for(int i=0;i<nStartPos.length;i++) $mm =$.  
{ r`u}n  
nStartPos = input.readLong(); }_XW?^/8  
nEndPos = input.readLong(); sh.xp8^)^>  
} :1u>T3L.z  
input.close(); khT&[!J{>  
} ,CW]d#P|  
catch(IOException e){e.printStackTrace ();} &_FNDJ>MCk  
catch(Exception e){e.printStackTrace ();} `;fh<kv  
} PK1j$ &F  
BmYU#h  
8)/i\=N3;  
private void processErrorCode(int nErrorCode) GkMNV7"m  
{ gd<8RVA  
System.err.println("Error Code : " + nErrorCode); oTZ?x}Z1  
} "?,3O2t  
SCeZt [  
RAKQ+Y"nl  
//停止文件下载 ANSvZqKh  
public void siteStop() aKs!*uo0H  
{ FtN1ZZ"<*  
bStop = true; []Cvma 1\  
for(int i=0;i<nStartPos.length;i++) bGRI^ [8#+  
fileSplitterFetch.splitterStop(); TRz~rW k  
ezTu1-m  
S-Va_ t$  
} /rp4m&!  
} Bp\io$(%  
//负责部分文件的抓取 C>cc!+n%H  
**FileSplitterFetch.java R#~}ZUk2  
*/ o^~6RZ  
package NetFox; Gb 61X6  
O%9Cq}*  
'R*gSqx~  
import java.io.*; ($(6]?J(?7  
import java.net.*; T(+F6d=1  
V5rnI\:7  
~ C5iyXR  
public class FileSplitterFetch extends Thread { $gDp-7  
n ! qm  
X@+:O-$  
String sURL; //File URL e<5+&Cj  
long nStartPos; //File Snippet Start Position HY#7Ctn3  
long nEndPos; //File Snippet End Position :{4G= UbAI  
int nThreadID; //Thread's ID 6bnAVTL5  
boolean bDownOver = false; //Downing is over vVyO}Q`  
boolean bStop = false; //Stop identical q" wi.&|  
FileAccessI fileAccessI = null; //File Access interface !|_ CXm T|  
MIa].S#  
7^sU/3z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WA Y<X:|We  
{ &ukNzV}VW  
this.sURL = sURL; *wt yyP@  
this.nStartPos = nStart; qh$D;t1=  
this.nEndPos = nEnd; {#QFDA  
nThreadID = id; 2`5(XpYe  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7tAWPSwf  
} mXc/sh")X  
&o"Hb=k<  
}=A6Jv(j  
public void run() T.ub! ,Y  
{ rQ}4\PTi  
while(nStartPos < nEndPos && !bStop) qIjC-#a=m  
{ |L;'In  
W/oRt<:E  
N(vbo  
try{ OpxVy _5,  
URL url = new URL(sURL); R,Zuy( g  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y@eHp-[  
httpConnection.setRequestProperty("User-Agent","NetFox"); lk.Q6saI1  
String sProperty = "bytes="+nStartPos+"-"; F/j=rs,*|D  
httpConnection.setRequestProperty("RANGE",sProperty); @PwEom`a  
Utility.log(sProperty); ?]fBds=  
7P/j\frW  
IX7d[nm39  
InputStream input = httpConnection.getInputStream(); Ccz:NpK+  
//logResponseHead(httpConnection); qjR;c& qR  
8e>;E  
8g>jz 8  
byte[] b = new byte[1024];  >o.u,  
int nRead; 7vr)JT=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TeqFy(Dr  
{ "]c:V4S#`A  
nStartPos += fileAccessI.write(b,0,nRead); S-2xe?sb  
//if(nThreadID == 1) ?Tuh22J{Q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bDUGzezP<  
} s+zb[3}  
7]e]Y>wZap  
6/4OFvL1  
Utility.log("Thread " + nThreadID + " is over!"); "vLqYc4$  
bDownOver = true; nOQ+oqM<  
//nPos = fileAccessI.write (b,0,nRead); mf}?z21vD  
} 3tXtt@Yy  
catch(Exception e){e.printStackTrace ();} yWzvE:!)  
} 83R"!w18  
} @Jvw"=  
q<c).4  
[&NF0c[i  
//打印回应的头信息 R$6Y\ *L[  
public void logResponseHead(HttpURLConnection con) yE"hgdL  
{ )W57n)]  
for(int i=1;;i++) d1y(Jt  
{ 8.k"kXU@n  
String header=con.getHeaderFieldKey(i); IR/0gP  
if(header!=null) 0@AK  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Z{ fKr  
Utility.log(header+" : "+con.getHeaderField(header)); wCmwH=O  
else ?\vJ8H[bD  
break; E}NX+ vYF  
} WDzov9ot  
} NmB0CbB  
!Z=`Wk5  
 g<,v2A  
public void splitterStop() Eq.c;3  
{ "#4PU5.  
bStop = true; -D!F|&$  
} I*lq0&  
boN)C?"^h  
*[.\ S3K`  
} 6Ir ?@O1'!  
T$}<So|  
42m`7uQ  
/* 8 6L&u:o:  
**FileAccess.java h)y"?Jj  
*//文件访问(定位,写) :hMuxHr  
package NetFox; )3)L  
import java.io.*; mnil1*-c0  
&q":o 'q  
tOspDPSXX  
public class FileAccessI implements Serializable{ 7FMHz.ZRE  
%{}Jr`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3tr?-l[N\  
RandomAccessFile oSavedFile; $ng\qJ"HF  
long nPos; PI{sO |  
}1 _gemlf  
Wb4sfP_  
public FileAccessI() throws IOException aaaC8;.  
{ tkuN$Jl  
this("",0); u8?ceM^r  
} R8],}6,;E}  
zb;' }l;+  
l>qCT  
public FileAccessI(String sName,long nPos) throws IOException L3<XWpv  
{ hlUF9}  
oSavedFile = new RandomAccessFile(sName,"rw"); Nju7!yVM_  
this.nPos = nPos; W1: o2 C7  
oSavedFile.seek(nPos); ,Y`C7Px  
} |Cen5s W&  
H<NYm#a"  
1/&j'B  
public synchronized int write(byte[] b,int nStart,int nLen) P%/+?(?  
{ -9aht}Z  
int n = -1; 'm2,7]  
try{ 5T   
oSavedFile.write(b,nStart,nLen); ?L'k2J  
n = nLen; S>"dUM  
} ,#c-"x Y  
catch(IOException e) e,4!/|H:  
{ =r_ S MTu  
e.printStackTrace (); Mb<KZ_wYOX  
} QPFpGS{d  
g:2/!tujL  
mB1)!  
return n; rBny*!n  
} BR0bf5T/  
9s7B1Pf  
Pu9.Uwx  
} lZ.,"F@  
Q`//HOM,  
G)e 20Mst  
/* k~q[qKb8y:  
**SiteInfoBean.java [j![R  
*/ <v2R6cj5  
package NetFox; i5AhF\7F9  
(=PnLP  
>Y \4 v}-  
public class SiteInfoBean { st+Kz uK  
BryMq !  
ZR#UoYjupb  
private String sSiteURL; //Site's URL PkVXn  
private String sFilePath; //Saved File's Path }F3Z~  
private String sFileName; //Saved File's Name zc2,Mn2  
private int nSplitter; //Count of Splited Downloading File yqBu7E$X  
Iy,)>V%iZV  
Jz|(B_U  
public SiteInfoBean() xv%}xeE V  
{//nSplitter的缺省值为5 RV($G8U  
//default value of nSplitter is 5 k[zf`x^  
this("","","",5); ?.Kl/8ml  
} zh4o<f:-  
snK9']WXo  
H~$|y9>qI  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #`W8-w  
{ XG [%oL  
sSiteURL= sURL; -#i%4[v  
sFilePath = sPath; 3{_+dE"9  
sFileName = sName; d@l;dos),  
this.nSplitter = nSpiltter; CjST*(,b  
<y'ttxeS  
Fj&vWj`*  
} %(e=Q^=  
_ Po9pZ  
Ec[:6}  
public String getSSiteURL() >N3{*W  
{ MD On; Af>  
return sSiteURL; A9R}74e4g  
} 3n/L; T,X  
Jg Xbs+.  
Z g'[.wov  
public void setSSiteURL(String value) 2 43DdIG$  
{ /J6CSk  
sSiteURL = value; -5qO}^i$a  
} 1";~"p2(  
6 S&#8l  
 o _CVZ  
public String getSFilePath() /;lk.-yU  
{ *CG2sAeB  
return sFilePath; m&%N4Q~X>  
} m:^@AR1%d  
Kr#=u~~M  
]I]dwi_g)  
public void setSFilePath(String value) _ <~05Eh  
{ '0=U+Egp  
sFilePath = value; 4 '+)9&g  
} @2u<Bh}}  
J)-owu;  
7]^Cg;EtM:  
public String getSFileName() *\`C! r  
{ jsG9{/Ov3  
return sFileName;  [:k'VXL  
} _m&VdIPO  
zZRqb/20  
ysa"f+/  
public void setSFileName(String value) 6RF01z|~_  
{ ENmo^O#,u  
sFileName = value; e}?t[aK4#  
} P``hw=L  
y#MLxm  
a=J?[qrx  
public int getNSplitter() C VUDN2  
{ A1@-;/H3  
return nSplitter; sDF J  
} YU"Am !  
226s:\d  
&l.^UQ   
public void setNSplitter(int nCount) @<2pYIi 8  
{ *p-Fn$7\n  
nSplitter = nCount; }Q%>Fv  
} L=p.@VSZ  
} +-Dd*yD6<  
c`>\R<Z ]  
xvkof 'Q)  
/* dOhV`8l  
**Utility.java -`RJ k(  
*/ Y!`?q8z$G  
package NetFox; V.4j?\#%  
5[3hw4  
GWW@8GNI  
public class Utility { zZxP= c  
T'V(%\w  
]`NbNr]K  
public Utility() *Z]| Z4Q/`  
{ GWhZ Mj  
Z:*U/_G  
aw 7f$Fqk  
}  ZBXGu f  
lfA  BF  
//线程睡眠 ^DH*@M  
public static void sleep(int nSecond) 9,Mp/.T"\  
{ k@~-|\ooG  
try{ B -KOf  
Thread.sleep(nSecond); 5bw]cv$i  
} T/K.'92S  
catch(Exception e) $i1A470C  
{ \(C W?9)  
e.printStackTrace (); }.'%gJrS  
} miKi$jC}vq  
} AWi87q  
R',w~1RV'  
//日志 zbR.Lb  
public static void log(String sMsg) d3$<|mG$  
{ Lr^xp,_n  
System.err.println(sMsg); W>~%6K>p  
} H>] z=w~  
Pjy?&;GvT  
A)#sh) }Q  
public static void log(int sMsg) !$?@;}=  
{ KFhn}C3 i  
System.err.println(sMsg); YfalsQ8  
} q!TbM"  
} =4 D_-Q  
$O>@(K  
Jv<)/Km`  
/* Id*^H:]C#  
**TestMethod.java >(CoXSV5  
*/ 8.^U6xA  
package NetFox; ;?!rpj  
kziBHis!  
a(~Yr A%~  
public class TestMethod { u s0'7|{q  
=tNiIU  
Tc(R-Wi  
public TestMethod() {XXNl)%  
{ ///xx/weblogic60b2_win.exe S=g-&lK  
try{ <f6PULm  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HH#i.s2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }^<zVdwp  
SiteFileFetch fileFetch = new SiteFileFetch(bean); FNM"!z  
fileFetch.start(); _PbfFY #  
} Mh|`XO.5I  
catch(Exception e){e.printStackTrace ();} w3N%J>4_E  
&-:yn&f7  
\i+h P1 mz  
} ,m?D\Pru  
b1u'ukDP\  
E?mp6R]}%  
public static void main(String[] args) Q75^7Ga_  
{ -9I%   
new TestMethod(); \Sby(l  
} gJxVU41  
} c.Y8CD.tqL  
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