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http断点续传简单实现(java)

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/*  })w5`?Y  
**SiteFileFetch.java sAc)X!}  
*/ X]CaWxM  
package NetFox; d}415 XA  
import java.io.*; /L[:C=u  
import java.net.*; }`^<ZNkb/  
`}Hnj*  
MN)<Tr2f  
public class SiteFileFetch extends Thread { mKq9mA"(E  
Bp6Evi  
#wm)e)2@  
SiteInfoBean siteInfoBean = null; //文件信息Bean N4 mQN90t  
long[] nStartPos; //开始位置 j({L6</x  
long[] nEndPos; //结束位置 CGg6nCB  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ,|c_l)  
long nFileLength; //文件长度 QU4'x4YS  
boolean bFirst = true; //是否第一次取文件 i|d41u;@  
boolean bStop = false; //停止标志 j+ys&pDczm  
File tmpFile; //文件下载的临时信息 Y2D) $  
DataOutputStream output; //输出到文件的输出流 (}qLxZ/U  
$fvUb_n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) cE]kI,Fw,M  
public SiteFileFetch(SiteInfoBean bean) throws IOException FRF}V@~  
{ 6ensNr~ea  
siteInfoBean = bean; `")  I[h  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 6<~y!\4;F  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ,zyrBO0 Eq  
if(tmpFile.exists ()) >) :d38M  
{ bo"I:)n;  
bFirst = false; 1!NaOfP;@  
read_nPos(); dX3> j{_  
} fu&]t8MJC  
else mLYB6   
{ MR6vr.~  
nStartPos = new long[bean.getNSplitter()];  JuI,wA  
nEndPos = new long[bean.getNSplitter()]; jH G(d$h  
} aH#|LrdJ  
nBj7Q!lW  
Fu><lN7  
ozo8 Tr  
} liB>~DVC  
_0`O}  
5m3sjcp_  
public void run() t2$:*PvE  
{ U5PCj ]-Xt  
//获得文件长度 8UZE C-K  
//分割文件 JZ7-? o  
//实例FileSplitterFetch n C Z  
//启动FileSplitterFetch线程 Fy@D&j  
//等待子线程返回 %~[F^  
try{ - |'wDf?H  
if(bFirst) 1f:k:Y9i  
{ {gn[ &\  
nFileLength = getFileSize(); jHZ<G c  
if(nFileLength == -1) @'y"D  
{ $7*Ml)H!9  
System.err.println("File Length is not known!"); vtT:c.~d  
} m1hf[cg  
else if(nFileLength == -2) *\>2DUu\`  
{ , $=V  
System.err.println("File is not access!"); ,5*4%*n\  
} j?(QieBH  
else fe$WR~  
{ ),Rj@52l  
for(int i=0;i<nStartPos.length;i++) &_6:TqJ  
{ ,O+7nByi[V  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1$W!<:uh  
} ~}116K  
for(int i=0;i<nEndPos.length-1;i++) KP(Bu0S  
{ N@>S>U8C  
nEndPos = nStartPos[i+1]; EIfrZg7R  
} o_5@R+&  
nEndPos[nEndPos.length-1] = nFileLength; PTh Ya  
} s5dh]vNN  
} Lsz`nD5  
WveFB%@`;  
1,J.  
//启动子线程 x@ O:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wtKh8^:YD  
for(int i=0;i<nStartPos.length;i++) (qrT0D6  
{ YGO@X(ej,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5W48z%MN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fYi!Z/Ck2  
nStartPos,nEndPos,i); 6M9rC[h\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H6eGLg={  
fileSplitterFetch.start(); #Grm-W9E  
} L5W>in5(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $9~1s/('  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @:@rks&  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vX\e* v  
nEndPos = " + nFileLength); GS H{1VS_b  
// fileSplitterFetch[nPos.length-1].start(); wMoAvA_oS  
@!da1jN  
+*q@=P,  
//等待子线程结束 /~[R u  
//int count = 0; >>r:L3<!  
//是否结束while循环 jo*9QO  
boolean breakWhile = false; -G 'lyH  
YovY0nO  
v=>Gvl3&U  
while(!bStop) $\ '\@3o  
{ G;;~xfE'  
write_nPos(); 96avgyc  
Utility.sleep(500); luT8>9X^:a  
breakWhile = true; 86g+c  
c"ztrKQQ  
'Ap 5Aq  
for(int i=0;i<nStartPos.length;i++) M)7enp) F.  
{ V]}b3Y!(  
if(!fileSplitterFetch.bDownOver) 8E+l; 2  
{ jlBCu(.,_  
breakWhile = false; 3@L%#]xwi  
break; Cs{f'I  
} h~p}08  
} hd;I x%tq>  
if(breakWhile) rzHa&:Y  
break; $5r,Q{;$  
O@rb4(  
}TW=eu~  
//count++; ,GIqRT4K  
//if(count>4) MV}]i@ V  
// siteStop(); `%3p.~>  
} ErC[Zh"''  
N3<Jh  
E6k&r}  
System.err.println("文件下载结束!"); YC<I|&"  
} P1n@E*~V5  
catch(Exception e){e.printStackTrace ();} MavO`m&Cg  
} }q W aE  
G6 5N:  
@ `D6F;R  
//获得文件长度 8A.7=C' z  
public long getFileSize() 'wrpW#  
{ tqCg<NH.!m  
int nFileLength = -1; [@Y q^.6t  
try{ C6~dN& q  
URL url = new URL(siteInfoBean.getSSiteURL()); /p0LtUMu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); us%RQ8=k  
httpConnection.setRequestProperty("User-Agent","NetFox"); zQ}N mlk  
CaBS0' n  
RzQS@^u*F0  
int responseCode=httpConnection.getResponseCode(); ~*[4DQ[\  
if(responseCode>=400) iGLYM-  
{ 5i#w:O\cz  
processErrorCode(responseCode); VYo;[ue([  
return -2; //-2 represent access is error =osw3"ng  
} ZiYzsn  
W2h[NimU  
0K0=Ob^(e  
String sHeader; :OaQq@V  
[)>8z8'f  
[_b='/8  
for(int i=1;;i++) D(U3zXdO  
{ \|` Pul$  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }tO<_f))  
//Utility.log(in.readLine()); g8A{aHb1}  
sHeader=httpConnection.getHeaderFieldKey(i); 9mphj)`d;#  
if(sHeader!=null) ^!_7L4&y  
{ eh4"_t  
if(sHeader.equals("Content-Length")) _4B iF?1  
{ |o=ST  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5XO'OSdYq  
break; @]wem  
} M;V#Gm  
} FKnQwX.0  
else .0W4Dp  
break; C+m^Z[  
} h=r< B\Pa  
} JO{- P  
catch(IOException e){e.printStackTrace ();} wf< `J/7u  
catch(Exception e){e.printStackTrace ();} yPG\ &Bo  
)6 0f  
>@"3Q`  
Utility.log(nFileLength); IYg3ve`x  
Y_>-p(IH  
~V"cLTj"  
return nFileLength; C| IQM4  
} 4$DliP  
=k<4mlok^  
<;0N@  
//保存下载信息(文件指针位置) ';|>`<  
private void write_nPos() {^5<{j3e  
{ \If!5N  
try{  zn;Hs]G  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $o$Ev@mi  
output.writeInt(nStartPos.length); jsi#l  
for(int i=0;i<nStartPos.length;i++) c$<O0dI  
{ #0<y0uJ(y  
// output.writeLong(nPos); Sb9=$0%\  
output.writeLong(fileSplitterFetch.nStartPos); f(s3TLM  
output.writeLong(fileSplitterFetch.nEndPos); K-k.=6mS  
} t,1!`/\  
output.close(); 5QFXj)hR+4  
} E(3+o\w  
catch(IOException e){e.printStackTrace ();} &G|jzXE  
catch(Exception e){e.printStackTrace ();} 6O@ ^`T  
} m#'rI=}!  
Q1I_=fT  
*5_ 8\7d  
//读取保存的下载信息(文件指针位置) y_4krY|Zx  
private void read_nPos() #JR,C -w  
{ &c?hJ8"  
try{ Ed0>R<jR9  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q|$>H6H4b  
int nCount = input.readInt(); W*rU,F|9  
nStartPos = new long[nCount]; ,{ L;B  
nEndPos = new long[nCount]; f'`nx;@X  
for(int i=0;i<nStartPos.length;i++) Re,$<9V  
{ s!;VUr\  
nStartPos = input.readLong(); pg}+lYGP  
nEndPos = input.readLong(); .UhBvHH  
} ZDkD%SCy  
input.close(); ,dj* p ,J  
} CVSsB:H6e  
catch(IOException e){e.printStackTrace ();} s@)"IdSA(  
catch(Exception e){e.printStackTrace ();} EfBVu  
} Ril21o! j  
&Wz`>qYL*  
BUA6(  
private void processErrorCode(int nErrorCode) n:^"[Le  
{ 5ih"Nds[H  
System.err.println("Error Code : " + nErrorCode); HMS9y%zl/  
} :OQ:@Yk  
$,QpSK`9i  
E4v_2Q -w  
//停止文件下载 #u<o EDQ  
public void siteStop() 51ajE2+X&  
{ ,F`KQ )\"  
bStop = true; sAD P~xvU  
for(int i=0;i<nStartPos.length;i++) K)Xs L  
fileSplitterFetch.splitterStop(); W]yClx \  
+G!jKta7B  
;4/dk_~p]  
} D"x$^6`c}  
} F@K*T2uh  
//负责部分文件的抓取 q ~Q)'*m  
**FileSplitterFetch.java ,JQxs7@2k  
*/ 0n<(*bfW  
package NetFox; w^due P7J  
$uFh$f  
Q{l*62Bx  
import java.io.*; v<7Gln  
import java.net.*; D _bkUR1  
+{C9uY)$vf  
`J=1&ae{  
public class FileSplitterFetch extends Thread { >\?z37 :T  
Yf!*OGF  
eb.cq"C  
String sURL; //File URL @( n^S?(  
long nStartPos; //File Snippet Start Position 16[-3cJ T  
long nEndPos; //File Snippet End Position `Ge+(1x  
int nThreadID; //Thread's ID jqX@&}3@  
boolean bDownOver = false; //Downing is over >Z2,^5P{  
boolean bStop = false; //Stop identical /\-2l+y>J  
FileAccessI fileAccessI = null; //File Access interface =,C9O  
x'M^4{4[  
y3KcM#[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ra9cD"/J &  
{ =##s;zj(%  
this.sURL = sURL; i (%tHa37  
this.nStartPos = nStart; gaw4NZd)0  
this.nEndPos = nEnd; hLyTUt~\L  
nThreadID = id; r{q}f)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q9yGQu  
} =~\]3g  
Xb<DpBrk  
I NPYJ#%  
public void run() ^)hAVf~E  
{ @m/;ZQ  
while(nStartPos < nEndPos && !bStop) #j^('K|  
{ Wiq{wxe  
joChML_  
O/D Af|X|  
try{ q4 Oxs  
URL url = new URL(sURL); 7ZV~op2Q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y NrinYw  
httpConnection.setRequestProperty("User-Agent","NetFox"); T}n}.JwU  
String sProperty = "bytes="+nStartPos+"-"; J+}+ "h~.  
httpConnection.setRequestProperty("RANGE",sProperty); {ywXz|TP  
Utility.log(sProperty); wUK7um  
o9m  
tIGVB+g{F  
InputStream input = httpConnection.getInputStream(); B=Zl&1  
//logResponseHead(httpConnection); lJ:M^.Em0  
d`9W  
jF38kj3O7  
byte[] b = new byte[1024]; c?!YFm  
int nRead; ${eY9-r_%  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /B,:<&_-  
{ RHwaJ;:)#  
nStartPos += fileAccessI.write(b,0,nRead); ? o~:'Z  
//if(nThreadID == 1) 861i3OXVE>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pKt-R07*  
} x7P([^i  
6o=qJ`m[?  
Q;$ 9qOF  
Utility.log("Thread " + nThreadID + " is over!"); a>wfhmr  
bDownOver = true; eeW' [  
//nPos = fileAccessI.write (b,0,nRead); 5:Yck<  
} >aEL;V=}P  
catch(Exception e){e.printStackTrace ();} -A/ds1=;  
} w=f0*$ue+w  
} H+4=|mkQ  
M"=8O>NZ2  
[_y9"MMwn  
//打印回应的头信息 xn(+G$m  
public void logResponseHead(HttpURLConnection con) hq/J6 M  
{ ,M\j%3  
for(int i=1;;i++) ss? ]  
{ _Ry_K3K  
String header=con.getHeaderFieldKey(i); 33Ssylno  
if(header!=null) KxO/]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x}tKewdOSe  
Utility.log(header+" : "+con.getHeaderField(header)); =2^Vgc  
else [RAj3Fr0  
break; `WH[DQ  
} JNh=fvO2i  
} SHMl%mw  
1#grB(p?  
n!GWqle  
public void splitterStop() y L*LJ  
{ f#@S*^%V$  
bStop = true; WK pUn8&N  
} LO"_NeuL  
RnHQq'J|\  
)T>8XCL\}  
} 82lr4  
{tPnj_|n<  
:@.C4oq  
/* m&Lt6_vi  
**FileAccess.java HtxLMzgz<<  
*//文件访问(定位,写) br b[})}  
package NetFox; ya:sW5fk  
import java.io.*; j5kA^MTG  
^w>&?A'!  
aiYo8+{!#  
public class FileAccessI implements Serializable{ kEO1TS  
7'Lp8  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aC`Li^  
RandomAccessFile oSavedFile; }/20%fP  
long nPos; y =R aJm  
NdZ)[f:2  
}d_<\  
public FileAccessI() throws IOException DB#$~(o  
{ `%|u!  
this("",0); *xPB<v2N:P  
} ugno]5Ni  
Qh^R Ax  
/mc*Hc 8R8  
public FileAccessI(String sName,long nPos) throws IOException @8|Gh]\P  
{ D-6  
oSavedFile = new RandomAccessFile(sName,"rw"); ,s0 9B  
this.nPos = nPos; pDGT@qJ  
oSavedFile.seek(nPos); Rfht\{N 7  
} <KtBv Ip]  
5:c;RRn  
+kM\ D~D1  
public synchronized int write(byte[] b,int nStart,int nLen) {ih:FcI  
{ ;d4 y{  
int n = -1; 6z Ay)~  
try{ Jz0K}^Dj[  
oSavedFile.write(b,nStart,nLen); "=qv#mZ#9  
n = nLen; z=qWJQ  
} mmHJ h\2v  
catch(IOException e) CJp-Y}fGEA  
{ ZPl PN;J^1  
e.printStackTrace (); Tw x{' S  
} H<,bq*@  
Uj,g]e 8e  
*6XRjq^#  
return n; V{0%xz #  
} }t\ 10nQ  
?~,JY  
gwiR/(1  
} Tv\HAK<N  
~ 7}]  
ilv_D~|  
/* 4`s)ue  
**SiteInfoBean.java `y2ljIWJ  
*/ -bA!PeI  
package NetFox; Pg Syt  
X'@'/[?  
RJx{eck%  
public class SiteInfoBean { zka?cOmYF[  
^sV|ck  
.Vmtx  
private String sSiteURL; //Site's URL + 8f>^*:u  
private String sFilePath; //Saved File's Path 2 5Q+1  
private String sFileName; //Saved File's Name +`| mJa  
private int nSplitter; //Count of Splited Downloading File <7^Kt7k  
3p_b8K_bG  
@bT3'K-4  
public SiteInfoBean() dQ<(lzS~  
{//nSplitter的缺省值为5 g5}lLKT  
//default value of nSplitter is 5 ]YsR E>  
this("","","",5); B9*Sfw%  
} @^!\d#/M  
\!<"7=(J{4  
b/nOdFO@  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q2"WV  
{ gLD{1-v  
sSiteURL= sURL; f*<ps o  
sFilePath = sPath; B'p5M.6d#:  
sFileName = sName; b66R}=P l  
this.nSplitter = nSpiltter; [/OQyb4F<  
xl8#=qmCD  
y\#o2PVmY  
} nhewDDu  
3u_oRs  
b@ 6:1x  
public String getSSiteURL() Fc'[+L--Q  
{ \5hw9T&[B  
return sSiteURL; fLNag~  
} GJ`UO  
RM,'o[%  
+9zA^0   
public void setSSiteURL(String value) ~KRnr0  
{ q 5p e~  
sSiteURL = value; vLDi ;  
} )b92yP{  
\f"1}f  
*S4aF*Qk  
public String getSFilePath() TKOP;[1h  
{ 1Nj=B_T  
return sFilePath; f=m/ -mAA  
} o?wt$j-  
&$#99\ /  
.S!-e$EJ  
public void setSFilePath(String value) O>AFF@=  
{ Pq?*C;D  
sFilePath = value; v9rVpYc"  
} o1k#."wHr  
QKccrAo  
FJwt?3\u5  
public String getSFileName() 7`fY*O6   
{ Dtt-|_EMS  
return sFileName; X *O9JGh  
} N09KVz2Q  
>vVw!.fJ  
-:S IS`0s  
public void setSFileName(String value) El (/em  
{ 8l23%iWxe  
sFileName = value; JZ=5Bpw  
} {ma;G[!  
GV8)Kor%  
kA^A mfba  
public int getNSplitter() a,n93-m(m  
{ jNc<~{/  
return nSplitter; GNU;jSh5  
} s;1e0n  
sPCMckt  
|>2: eH  
public void setNSplitter(int nCount) CH;;V3  
{ _~A~+S}  
nSplitter = nCount; DYRE1!  
} A1-qtAO]  
} ZEGd4_ux  
0 d4cE10  
85z;Zt0{  
/* cZi[(K  
**Utility.java w>vH8f  
*/ KlU qoJ;"  
package NetFox; d#\W hRE  
"2;N2=~7  
x=,8[W#XT  
public class Utility { GN%(9N'W  
T~J? AKx  
]l[2hy= cV  
public Utility() l>7r2;  
{ J]fS({(\I  
|zpx)8Q  
?@UAL .y  
} GMm'of#  
A5XR3$5P  
//线程睡眠 r1Z<:}ZwK  
public static void sleep(int nSecond) r )b<{u=]  
{ (WE,dY+.  
try{ }-p,iTm  
Thread.sleep(nSecond); zu<3^=3  
} @^? XaU  
catch(Exception e) YwAnqAg  
{ kon=il<@  
e.printStackTrace (); Ei~f`{i  
} 'qy#)F  
} 7lU.Ni t  
ow.j+ <M  
//日志 oT3Y!Y3=<  
public static void log(String sMsg) #C\4/g? =,  
{ Jqru AW<  
System.err.println(sMsg); >Z\BfH  
} p5<2N  
/2@["*^$  
4;*f1_;f~  
public static void log(int sMsg) %-j&e44  
{ 0{R/<N  
System.err.println(sMsg); I/B1qw;MN  
} xK;e\^v  
} "^%Z'ou  
(p |DcA]BX  
Zq*eX\#C  
/* uA\J0"0; }  
**TestMethod.java \L[i9m|e  
*/ Z;b+>2oL  
package NetFox; 1S%}xsR0  
" s]y!BLk  
>&Fa(o;*  
public class TestMethod { NHiq^ojk  
rAXX}"l6s  
|Td5l?  
public TestMethod() 6fwY$K\X  
{ ///xx/weblogic60b2_win.exe T=\!2gt  
try{  r(`nt-o@  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7& 6Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HomN/wKh  
SiteFileFetch fileFetch = new SiteFileFetch(bean); i&Kz*,pt  
fileFetch.start(); $(q8y/,R*-  
} ]}LGbv"`A  
catch(Exception e){e.printStackTrace ();} xjq0D[  
VzwPBQ -  
@2' %o<lF  
} (ZPXdr  
7ZFJexN]  
o4)hxs  
public static void main(String[] args) TnE+[.Qu  
{ /F~X,lm*~  
new TestMethod(); +R[4\ hC0Y  
} oJY[{-qW  
} #@Y/{[s|@  
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