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http断点续传简单实现(java)

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/* 'N&s$XB,  
**SiteFileFetch.java uZP( -}  
*/ Qqd+=mgc  
package NetFox; #UnGU,J  
import java.io.*; QZ5%nJme_  
import java.net.*; !MOcF5M  
PkOtg[Z  
ZC&~InN  
public class SiteFileFetch extends Thread { /AIFgsaY  
; X/'ujg  
:FixLr!q  
SiteInfoBean siteInfoBean = null; //文件信息Bean m~@Lt~LZs  
long[] nStartPos; //开始位置 G&yF9s)Lvs  
long[] nEndPos; //结束位置 ^J@ Xsl  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ;?gR,AKZ  
long nFileLength; //文件长度 +p-S36K~,7  
boolean bFirst = true; //是否第一次取文件 yg%T{hyzH  
boolean bStop = false; //停止标志 (OG>=h8?  
File tmpFile; //文件下载的临时信息 CbMClnF  
DataOutputStream output; //输出到文件的输出流 $cGV)[KWp@  
O_D;_v6Ii+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) InG<B,/W?  
public SiteFileFetch(SiteInfoBean bean) throws IOException ^Uldyv/  
{ K&&YxX~ 3  
siteInfoBean = bean; ?YM0VB,y  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); g:>dF#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); n* z;%'0  
if(tmpFile.exists ()) xQ=L2pX  
{ ,f .#-  
bFirst = false; <$ %Y#I'zX  
read_nPos(); VKr oikz@]  
} &RlYw#*1.  
else 8yGo\\=T  
{ aV n+@g<.  
nStartPos = new long[bean.getNSplitter()]; {z# W-  
nEndPos = new long[bean.getNSplitter()]; PR>%@-Vgj  
} L ~$&+g  
P1ynCe  
Bs-MoT!  
."j*4  
} ZQ~EaI9R  
.a|ROjd!  
EkP(] F  
public void run() &^ =Y76  
{ (XQl2C  
//获得文件长度 B)ibxM(n*  
//分割文件 %U$%x  
//实例FileSplitterFetch (P nrY~9  
//启动FileSplitterFetch线程 =(,dI [v  
//等待子线程返回 \'x?VVw  
try{ ~ [=2d a  
if(bFirst) \fC}l Ll  
{ .7H* F9  
nFileLength = getFileSize(); MLn?t^v-  
if(nFileLength == -1) G]I^zd&P  
{ ":^cb =  
System.err.println("File Length is not known!"); d\rs/ee  
} ;hPo5uZQ  
else if(nFileLength == -2) GnW_^$Fs  
{ -KCQ!0\F  
System.err.println("File is not access!"); QsPL^ Ny  
} <V*M%YWs  
else ;<v9i#K5  
{ oFS)3.  
for(int i=0;i<nStartPos.length;i++) o(5 ( ]bJ  
{ mvBUm-X  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 7A>glZ/x  
} _+nlm5  
for(int i=0;i<nEndPos.length-1;i++) y &%2  
{ N:rnH:g+:  
nEndPos = nStartPos[i+1]; 12yX`9h>  
} 2aGK}sS6  
nEndPos[nEndPos.length-1] = nFileLength; d#nKTqSg  
} <k2]GI-}h  
} nL* SNQ_  
51x)fZQ  
Edav }z  
//启动子线程 !CuLXuM  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Og<UW^VR  
for(int i=0;i<nStartPos.length;i++) YS&Q4nv-  
{ ^1+&)6s7V  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \YsYOFc|  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9@z"~H  
nStartPos,nEndPos,i); .cm$*>LW:x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :S{+|4pH  
fileSplitterFetch.start(); [y$sJF7;I  
} TfqQh!Y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NpYzN|W:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [ f`V_1d3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vh^,8pPy  
nEndPos = " + nFileLength); VBI~U?0  
// fileSplitterFetch[nPos.length-1].start(); b$'}IWNV  
u:D,\`;)  
J;7O`5J  
//等待子线程结束 mGqT_   
//int count = 0; fRd^@@,[  
//是否结束while循环 v/WvT!6V`  
boolean breakWhile = false; |0/~7l  
~!W{C_*N  
_8"%nV  
while(!bStop) /0qLMlL$  
{ B@2VI 1%  
write_nPos(); >~k"C,6  
Utility.sleep(500); YV>]c9!q  
breakWhile = true; X Sw0t8  
2N:|BO>  
cp>1b8l6?  
for(int i=0;i<nStartPos.length;i++) /__@a&9t  
{ o Kfm=TbY  
if(!fileSplitterFetch.bDownOver) [Dq!t1  
{ Qtpw0t"  
breakWhile = false; DZ Q=Sinry  
break; Ljjuf=]  
} BSB;0OM  
} G\ht)7SGgf  
if(breakWhile) &*N;yW""f  
break; F"Y.'my8  
Sq,x57-  
Cl5l+I\1  
//count++; &I$MV5)u  
//if(count>4) ("B[P/  
// siteStop(); 3@/\j^U  
} h+7THMI  
gK8{=A0c  
zn'F9rWx>  
System.err.println("文件下载结束!"); F"<TV&xf  
} &{c.JDO  
catch(Exception e){e.printStackTrace ();} A7qKY-4B  
} .v{ok,&  
o1 kY|cnGH  
mew,S)dq!  
//获得文件长度 9c@."O`  
public long getFileSize() +bw>9VmG  
{ AsW!GdIN  
int nFileLength = -1; hc;8Vsa  
try{ RrGFGn{  
URL url = new URL(siteInfoBean.getSSiteURL()); MIJ^ n(-G  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &6`h%;a/&  
httpConnection.setRequestProperty("User-Agent","NetFox"); 58@YWv Ak  
EBX+fzjQo  
=k\V~8XZ  
int responseCode=httpConnection.getResponseCode(); fGtUr _D  
if(responseCode>=400) j:;[Y`2  
{ |aovZ/b4  
processErrorCode(responseCode); :Ej#qYi  
return -2; //-2 represent access is error )E.!jL:g  
} rVE!mi]%  
K*_5M  
m ["`Op4  
String sHeader; V_T.#"C4=z  
pp#xN/V#a  
~<?+(V^D  
for(int i=1;;i++) \qA g] -  
{ n5~7x   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N%k6*FBp~  
//Utility.log(in.readLine()); .m]"lH*  
sHeader=httpConnection.getHeaderFieldKey(i); Oist>A$Z  
if(sHeader!=null) ,X05&'@Z  
{ a$*)d($  
if(sHeader.equals("Content-Length")) N:]71+  
{ Wz~=JvRHh  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]c.1&OB7o  
break; 1yS [;  
} KTm^0:V[Oy  
} ]b"Oy}ARW  
else bZE;}d  
break; t0 1@h_ WS  
} NT6OGBl&  
} 1gwnG&  
catch(IOException e){e.printStackTrace ();} S~9K'\vO  
catch(Exception e){e.printStackTrace ();} 3:Mq4 0]x  
CHeU?NtFps  
Stkyz:,(  
Utility.log(nFileLength); Ca&5"aki  
iz&$q]P8  
avmuI^LLs  
return nFileLength; 4' ym vR  
} L"|~,SVF  
 jIMT&5k  
-_bnGY%,  
//保存下载信息(文件指针位置) *f[nge&.  
private void write_nPos() )]/gu\90  
{ kPm{tc  
try{ ETw7/S${  
output = new DataOutputStream(new FileOutputStream(tmpFile)); D`?=]Ysz(  
output.writeInt(nStartPos.length); J3F-Yl|  
for(int i=0;i<nStartPos.length;i++) LyaFWx   
{ aL9 yNj}2  
// output.writeLong(nPos); /A8ua=Kn  
output.writeLong(fileSplitterFetch.nStartPos); 7hs1S|  
output.writeLong(fileSplitterFetch.nEndPos); J|9kWjOf+i  
} Uq:WW1=kh  
output.close(); -bN;nSgb  
} OT*C7=  
catch(IOException e){e.printStackTrace ();} Z r}5)ZR.  
catch(Exception e){e.printStackTrace ();} _.9):i2<SF  
} x}Y  
|,3>A@  
TSGJ2u5ie%  
//读取保存的下载信息(文件指针位置) g[Z$\A?ZbZ  
private void read_nPos() #Sxk[[KwH*  
{ cjf 8N:4N0  
try{ i'w8Li  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 66P'87G  
int nCount = input.readInt(); #y<KO`Es  
nStartPos = new long[nCount]; iYqZBLf{S  
nEndPos = new long[nCount]; cBZK t  
for(int i=0;i<nStartPos.length;i++) 4GA9oLl  
{ x)Y?kVw21"  
nStartPos = input.readLong(); iP7 Cku}l  
nEndPos = input.readLong(); toq/G,N Q  
} @H{QHi  
input.close(); #DBg8  
} [Eeanl&x>  
catch(IOException e){e.printStackTrace ();} rd*`8B  
catch(Exception e){e.printStackTrace ();} 8T7ex(w  
} )w?DB@Tx  
%h}Qf&U_  
,buSU~c_Q  
private void processErrorCode(int nErrorCode) S(B$[)(  
{ qXOWCYqs  
System.err.println("Error Code : " + nErrorCode); WrA!'I  
} uwQ~4   
PQl^jS  
lO (MF  
//停止文件下载 [~3[Tu( C  
public void siteStop() b`%3>  
{ !cLdoX  
bStop = true; eP d  
for(int i=0;i<nStartPos.length;i++) ;Av=/hU  
fileSplitterFetch.splitterStop(); W'|NYw_B  
:]Nn(},  
:%6OFO$z  
} kPhdfF*Q  
} jL }bGD  
//负责部分文件的抓取 /5Od:n  
**FileSplitterFetch.java DjyqQ yq~  
*/ 7L%JCH#F  
package NetFox; Nl4,c[$C  
y:Wq;xEiDo  
~[_u@8l!mN  
import java.io.*; PykVXZ7j;  
import java.net.*; ;6 ?a8t@  
@q98ac*{  
o1kTB&E4B  
public class FileSplitterFetch extends Thread { IhIz 7.|  
%DK0s(*w0  
Y X`BX$  
String sURL; //File URL ^(j}'p,  
long nStartPos; //File Snippet Start Position 1^f7  
long nEndPos; //File Snippet End Position b< dwf[  
int nThreadID; //Thread's ID ',WnT:  
boolean bDownOver = false; //Downing is over "QKCZ8_C  
boolean bStop = false; //Stop identical YiO3.+H  
FileAccessI fileAccessI = null; //File Access interface  i/vo  
3WVH8Sb  
Fy; sVB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,Y:ET1:  
{ fY4I(~Q  
this.sURL = sURL; r}**^"mFy  
this.nStartPos = nStart; Qe[ejj1o:  
this.nEndPos = nEnd; &RJ*DAmL  
nThreadID = id; B\73 Vf  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kB)u@`</mV  
} h SeXxSb:  
?*zDsQ  
l&/V4V-  
public void run() :F |ll?  
{ xU1_L*tu '  
while(nStartPos < nEndPos && !bStop) |)+s,LT5  
{ tJM#/yT  
%,1xOl4l  
"t.Jv%0=  
try{ !K8Kw W|X  
URL url = new URL(sURL); 9{GEq@`7  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |erG cKk  
httpConnection.setRequestProperty("User-Agent","NetFox"); yTxrbE  
String sProperty = "bytes="+nStartPos+"-"; Vktc  
httpConnection.setRequestProperty("RANGE",sProperty); jIL+^{K<  
Utility.log(sProperty); &KYPi'C9!z  
(# c|San  
5K:'VX  
InputStream input = httpConnection.getInputStream(); .E:3I!dH7  
//logResponseHead(httpConnection); vg-Ah6BC{  
#n7F7X  
zA>LrtyK(=  
byte[] b = new byte[1024]; EED0U?  
int nRead; :>|dE%/e$  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y+aKk6(_W  
{  0"F|)  
nStartPos += fileAccessI.write(b,0,nRead); nO+-o;DbC  
//if(nThreadID == 1) 6MD9DqD  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ao U Pq  
} 2il`'X  
4,P(w+  
VnYcqeCm  
Utility.log("Thread " + nThreadID + " is over!"); /szwVA  
bDownOver = true; /fSsh;F  
//nPos = fileAccessI.write (b,0,nRead); 8\X-]Gh\^  
} 2Ij,OIcdBE  
catch(Exception e){e.printStackTrace ();} {>3J96  
} :cxA  
} +n%d,Pz  
@DNwzdP  
Y#5v5  
//打印回应的头信息 J2Mq1*Vpq  
public void logResponseHead(HttpURLConnection con) {E;oirv&  
{ T,oZaJ<  
for(int i=1;;i++) uq2C|=M-x\  
{ kz*6%Cg*~  
String header=con.getHeaderFieldKey(i); f<{f/lU@  
if(header!=null) 2oF1do;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dr)jB*yK  
Utility.log(header+" : "+con.getHeaderField(header)); .OpG2P  
else .6LlkM6[g  
break; _-T^YeQ/  
} bzXeG;c<7  
} oF~+L3&X  
:4r{t?ytXw  
dBkM~"  
public void splitterStop() a&Z,~Vp  
{ G J{XlH  
bStop = true; I&6M{,rnM  
} r;9 V7C  
{4$aA*  
DDq?4  
} %a?\y_a=b  
n) j0h-  
I 6'!b/  
/* p/qu4[Mm  
**FileAccess.java P6I<M}p  
*//文件访问(定位,写) Yr*!T= z  
package NetFox; S"t\LB*'Ls  
import java.io.*; ~dC.,"  
z1^3~U$}  
tVe =c  
public class FileAccessI implements Serializable{ I.'/!11>  
D<`M<:nq  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /9A6"Z  
RandomAccessFile oSavedFile; b BiTAP  
long nPos; r8tW)"?  
4TTrHs  
+c8t~2tuN  
public FileAccessI() throws IOException P }^Y"zF2  
{ XtQwLH+F  
this("",0);  "D'rsEh  
} ~.4y* &  
&lgzNC9g%  
~Zn|(  
public FileAccessI(String sName,long nPos) throws IOException AmZW=n2^  
{ {;|pcx\L6~  
oSavedFile = new RandomAccessFile(sName,"rw"); 3B='f"G  
this.nPos = nPos; ))dw[Xa  
oSavedFile.seek(nPos); 1G6 \}El95  
} C+t0Zen  
O')=]6CQ*  
h;#046-7  
public synchronized int write(byte[] b,int nStart,int nLen) 5UJ ?1"J  
{ zBK"k]rz  
int n = -1; }Q*J!OH  
try{  LJ;&02w@  
oSavedFile.write(b,nStart,nLen); ff7#LeB9  
n = nLen; !Eg2#a?  
} &8pGq./lr=  
catch(IOException e) !C|Z+w9Y  
{ 3 l}9'j  
e.printStackTrace (); ~;z] _`_Va  
} M~7Cb>%<  
VC0Tqk  
&Z3%UOY  
return n; 8f1M6GK?  
} Bd 0oA )i  
kBLFK3i  
6"o=`Sq  
} c&P/v#U_  
Qv`: E   
S?6 -I,]h  
/* s)fahc(@E  
**SiteInfoBean.java Q@W!6]*\  
*/ =)G]\W)m  
package NetFox; 6.a5%:  
d#XgO5eyO  
<.Pt%Kg^BS  
public class SiteInfoBean { $P#x>#+[A  
IN@o9pUjV  
h-|IZ}F7  
private String sSiteURL; //Site's URL v%c/eAF  
private String sFilePath; //Saved File's Path 7M _ mR Vh  
private String sFileName; //Saved File's Name G'u[0>  
private int nSplitter; //Count of Splited Downloading File mr/?w0(C  
k6J&4?xZ  
" dGN0i  
public SiteInfoBean() UmvnVmnv  
{//nSplitter的缺省值为5 J<0d"'  
//default value of nSplitter is 5 )HC/J-  
this("","","",5); ll1N`ke  
} b !y  
zc=G4F01  
{]cr.y]\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0%< hj  
{ G3`9'-2q@c  
sSiteURL= sURL; .%)uCLZr$  
sFilePath = sPath; x/CM)!U)  
sFileName = sName; P 4t@BwU$  
this.nSplitter = nSpiltter; |/H?\]7  
=4'V}p  
MU sF  
} 9a=>gEF],@  
f^*Yqa  
Woj5 yr  
public String getSSiteURL() & !ds#-  
{ i NfAn&  
return sSiteURL; =+K?@;?  
} ]{# =WTp]  
*l 4[`7|  
-)^vO*b 0  
public void setSSiteURL(String value) #R:&Irh  
{ ?>U=bA  
sSiteURL = value; +p63J  
} 9Bw#VQ  
}eW<P079  
mv#hy  
public String getSFilePath() $OdBuJA  
{ 'tw ]jMD  
return sFilePath; wggB^ }~  
} 6pSTw\/6  
49M1^nMvoo  
[T,^l#S1  
public void setSFilePath(String value) ?T_MP"  
{ EpNN!s=Q  
sFilePath = value; \/<VJB uV  
} 7I'C'.6iM  
~  z3J4s  
>W8"Ar  
public String getSFileName() 1P[x.t#  
{ UO&$1rV  
return sFileName; >V?0#f45@  
} h'};spv  
B~ i  
`7w-_o %  
public void setSFileName(String value) +a^gC  
{ y]+5Y.Cw$  
sFileName = value; k9OGnCW\  
} "FA. T7G  
7@>/O)>(AS  
]b; m~|9  
public int getNSplitter() xx>h J!  
{ C 'MR=/sd  
return nSplitter; !hZ: \&V  
} \Z3K ~  
d8vf kV B  
eK l; T  
public void setNSplitter(int nCount) -$o0P'Vx  
{ 7`;f<QNo  
nSplitter = nCount; iLZY6?_^  
} Ms,MXJtH  
} dt:$:,"   
a{r"$>0  
r9&m^,U  
/* yD7}  
**Utility.java kMurNA=  
*/ O 7 aLW  
package NetFox; ur8+k4] \"  
5Y^"&h[/  
:K]7(y7>  
public class Utility { h#O9TB  
|xcI~ X7Q  
El5} f4sl  
public Utility() K2yNI q_  
{ cbyzZ#WRb  
p9?kJKN  
^@AyC"K  
} -)oUb=Lk{  
[,Go*r  
//线程睡眠 }' AY#g  
public static void sleep(int nSecond) ; $80}TY '  
{ EZ .3Z`  
try{ )S%t) }  
Thread.sleep(nSecond); iBAP,cR?`  
} z``wqK  
catch(Exception e) /m"/#; ^l  
{ iO5g30l  
e.printStackTrace (); aim\ 3y~  
} 8]&:'  
} T8z?_ *k  
y0mNDze  
//日志 RSym9t90t  
public static void log(String sMsg) UTyV6~  
{ hk4t #Km  
System.err.println(sMsg); {owuYVm  
} ( ~5 M{Xh  
r)'vn[A  
|} b+$J  
public static void log(int sMsg) \6&Ml]1  
{ `9K5 ;]  
System.err.println(sMsg); 9m$;C'}Z  
} <Pt?N2]A|  
} Z)W8Of_  
)ciP6WzzbI  
I61S0l z/  
/* vlbZ5  
**TestMethod.java E^F<"mL*  
*/ 50N4J  
package NetFox; ~SQ xFAto  
~h@@y5<4  
0W*{ 1W  
public class TestMethod { L/tn;0  
P{n#^4  
hvw9i7#  
public TestMethod() >Dr(%z6CN  
{ ///xx/weblogic60b2_win.exe KN|<yF   
try{ }<A.zwB<i  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EYq?NL='  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [UzD3VPg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~#*C,4m  
fileFetch.start(); *pJGp:{6V?  
} ^)gyKl:E'  
catch(Exception e){e.printStackTrace ();} R}Lk$#S#  
4$&l`yWU+  
1^WGJ"1  
} `]eJF|"  
M-"j8:en  
f"5O'QHGQK  
public static void main(String[] args) LN5LT'CE   
{ DYr#?} 40  
new TestMethod(); 4@?0wV  
} Ocx"s\q(  
} j1K3|E  
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