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http断点续传简单实现(java)

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/* B]5G"4,  
**SiteFileFetch.java TClgywL  
*/ V<G=pPC'H  
package NetFox; e-e*%  
import java.io.*; k\wI^D  
import java.net.*; @EzO bE{  
*S=zJyAO  
O #S27.  
public class SiteFileFetch extends Thread { gN/6%,H}  
2';f8JLY  
.@(9v.:_u  
SiteInfoBean siteInfoBean = null; //文件信息Bean fI1,L"  
long[] nStartPos; //开始位置 7Q3a0`Iq  
long[] nEndPos; //结束位置 Fb9!x/$tGV  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 tgB\;nbB  
long nFileLength; //文件长度 [agp06 $D?  
boolean bFirst = true; //是否第一次取文件 HCTjFW>C  
boolean bStop = false; //停止标志 3,RaM^5dV  
File tmpFile; //文件下载的临时信息 SN/ e41  
DataOutputStream output; //输出到文件的输出流 |] 8Hh>  
Foc) u~  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9py *gN#  
public SiteFileFetch(SiteInfoBean bean) throws IOException /K<.$B8  
{ UuvI?D  
siteInfoBean = bean; n; fUwon  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9>na3ISh  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _MC\\u/C/  
if(tmpFile.exists ()) (r+#}z}  
{ 'CSIC8M<j  
bFirst = false; (R)(%I1Oz  
read_nPos(); ?E:L6,a  
} 98AX=%8  
else ^%pM$3ov  
{ &?mJL0fy  
nStartPos = new long[bean.getNSplitter()]; OfSHZ;,  
nEndPos = new long[bean.getNSplitter()]; <"Cacf g  
} yC]X&1,:z  
]5}C@W@_  
46cd5SLK  
DYKJVn7w  
} 4#^?-6  
\E3e vU  
ow{SsX  
public void run() k{q4Zz[  
{ <_~>YJ  
//获得文件长度 o|?bvFC  
//分割文件 W{!GL  
//实例FileSplitterFetch Eax^1 |6  
//启动FileSplitterFetch线程 * vMNv  
//等待子线程返回 6(uK5eD(!n  
try{ ToWtltCD  
if(bFirst) %8a886;2  
{ 8NRc+@f|m  
nFileLength = getFileSize(); <p74U( V  
if(nFileLength == -1) !K~:crUV|S  
{ xF4>G0  
System.err.println("File Length is not known!"); lSzLR~=Au  
} `Z:5E  
else if(nFileLength == -2) <cn{S`  
{ b=Y:`&o=[  
System.err.println("File is not access!"); xF4>D!T%8  
} tgPx!5U  
else Y]SX2kk(2  
{ ~Yw`w 2  
for(int i=0;i<nStartPos.length;i++) ZFAi9M  
{ ,@1.&!F4it  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "+6:vhP5  
} W+C@(}pt  
for(int i=0;i<nEndPos.length-1;i++) "V;5Lp b  
{ feH|sz`e  
nEndPos = nStartPos[i+1]; }Ra'`;D$  
} 1k *gbXb  
nEndPos[nEndPos.length-1] = nFileLength; Uz`K#Bz   
} DFKumw>!  
} CAhkv0?8  
Gw5j6  
_*SA_.0  
//启动子线程 ymxYE#q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m.}Yn,  
for(int i=0;i<nStartPos.length;i++) 5g{F-  
{ :bhpYEUMx  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^K#PcPF-j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t'@qb~sf  
nStartPos,nEndPos,i); $YX\&%N  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1UHStR  
fileSplitterFetch.start(); 61W ms@D%  
} 4t0B_o"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sf2pU!5n^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >(} I7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mrzrQ@sN  
nEndPos = " + nFileLength); v~2$9x!9  
// fileSplitterFetch[nPos.length-1].start(); RiY9[ec2  
AI|8E8h+D  
o6PDCaT7  
//等待子线程结束 Tjfg[Z/x  
//int count = 0; LyRU2A  
//是否结束while循环 FM)Es&p&  
boolean breakWhile = false; YtzB/q8I  
pt rQ~m-  
TfYXF`d  
while(!bStop) K9#=@}!3L  
{ ]+SVQ|v0  
write_nPos(); /=5YHq>  
Utility.sleep(500); I'_u4  
breakWhile = true; us2X:X)  
'n9<z)/,!  
a19yw]hF5  
for(int i=0;i<nStartPos.length;i++) Y 7a<3>  
{ SOq{`~,4B  
if(!fileSplitterFetch.bDownOver) ~qG`~/7  
{ uK:?6>H  
breakWhile = false; =lzRx%tm  
break;  f:_\S  
} TfD]`v`]   
} B}%B4&Ij  
if(breakWhile) =Mb1)^m  
break; iG\ ]  
dA`.  
D]H@Sx  
//count++; ^=H. .pr  
//if(count>4) SxHj3,`#C  
// siteStop(); GvL)SVv?  
} v[r5!,F  
1 h.=c  
)}-,4Iu%  
System.err.println("文件下载结束!"); &B</^:  
} S}/?L m}  
catch(Exception e){e.printStackTrace ();} ?Mb 'l4  
} *nv%~t   
L"w% ew  
L8&$o2+07r  
//获得文件长度 '.sS"QdN  
public long getFileSize() I.f)rMl+h  
{ +J^-B}v  
int nFileLength = -1; z$VA]tI(  
try{ *?zyF@K{%  
URL url = new URL(siteInfoBean.getSSiteURL()); 5Iv3B|u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2{v$GFc/  
httpConnection.setRequestProperty("User-Agent","NetFox"); TTS.wBpR,  
%>dCAj"  
u7_IO  
int responseCode=httpConnection.getResponseCode(); 9t.u9C=!F  
if(responseCode>=400) v&hQ;v  
{ YceX)  
processErrorCode(responseCode); :N \j@yJK  
return -2; //-2 represent access is error U#I 8Rd I,  
} p7UdZOi2  
`aj;FrF  
7X h'VOljB  
String sHeader; Op&i6V}<s  
h&$7^P  
td:GZ %  
for(int i=1;;i++) }tvLe3O  
{ l\PDou@5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j4ARGkK5B  
//Utility.log(in.readLine()); MeXzWLH  
sHeader=httpConnection.getHeaderFieldKey(i); bbDl?m&bq  
if(sHeader!=null) GOT@  
{ (v11;kdJB  
if(sHeader.equals("Content-Length")) WOW:$.VO^  
{ uM!$`JN  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 39xAh*}G]  
break; U*G8 }W  
} BO#XQ,  
} ~i)m(65:  
else {*gO1TZt9  
break; LciSQ R!  
} 9] i$`y  
} w4m -DR5  
catch(IOException e){e.printStackTrace ();} AY{-Hf&  
catch(Exception e){e.printStackTrace ();} 9~bl  
PGaB U3  
zYCrfr  
Utility.log(nFileLength); :[;]6;  
F/MzrK\':m  
&+@~;p 5F  
return nFileLength; f`zH#{u  
}  Q.3oDq  
MIblx  
^6tcB* #A  
//保存下载信息(文件指针位置) l98.Hb7  
private void write_nPos() huMNt6P[  
{ fOE8{O^W  
try{ L/2{}l>D  
output = new DataOutputStream(new FileOutputStream(tmpFile)); So&an !  
output.writeInt(nStartPos.length); zh5$$*\  
for(int i=0;i<nStartPos.length;i++) J^}w,r *=  
{ o5!"dxR  
// output.writeLong(nPos); Q_ zGs6  
output.writeLong(fileSplitterFetch.nStartPos); *h+@a  
output.writeLong(fileSplitterFetch.nEndPos); Pm2T!0  
} .T*K4m{b0  
output.close(); X6+2~'*t  
} I%.96V  
catch(IOException e){e.printStackTrace ();} ~hubh!d=  
catch(Exception e){e.printStackTrace ();} OQ[E-%v1 R  
} t7A '  
KC+C?]~M  
qTbY'V5A  
//读取保存的下载信息(文件指针位置) 1ga-8&!  
private void read_nPos() v35wlt^}  
{  3kAmRU  
try{ yv.Y-c=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m!{}Y]FZn  
int nCount = input.readInt(); I)wjTTM5  
nStartPos = new long[nCount]; 5|&:l8=  
nEndPos = new long[nCount]; s0,\[rM  
for(int i=0;i<nStartPos.length;i++) *?;<buJb?  
{ OYcf+p"<\  
nStartPos = input.readLong(); JfJUOaL  
nEndPos = input.readLong(); +-b:XeHSZ  
} ?y.q<F)  
input.close(); h8IjTd]z{$  
} 6XVr-ef  
catch(IOException e){e.printStackTrace ();} [iJU{W  
catch(Exception e){e.printStackTrace ();} Hwr# NKz-  
} kbqG)  
)_*<uSl  
d2b  L_  
private void processErrorCode(int nErrorCode) +UzFHiGy#  
{ ]SNA2?q  
System.err.println("Error Code : " + nErrorCode); ZTCzD8  
} Yzr RnVr  
PUMh#^g}  
5k0r{^#M  
//停止文件下载 l?>sLKo9  
public void siteStop() /u9Md3q*'  
{ v3b[08 F  
bStop = true; 6pkZ8Vp:  
for(int i=0;i<nStartPos.length;i++) ,2Y P D4  
fileSplitterFetch.splitterStop(); b;wf7~a*  
OBGA~E;%  
3t  
} GCN(  
} >Ab>"!/'K  
//负责部分文件的抓取 Yg 8AMi  
**FileSplitterFetch.java 2ckAJcpEb/  
*/ B{fPj9Y0  
package NetFox; J(BtGGU'  
T[mo PD5  
!PN;XZ~{  
import java.io.*; nC^|83  
import java.net.*; Z]$RO  
[ emUyF  
X~/hv_@  
public class FileSplitterFetch extends Thread { EJ$-  
n^8LF9r  
#;Yn8'a~  
String sURL; //File URL DNsDEU  
long nStartPos; //File Snippet Start Position ]~my<3j}or  
long nEndPos; //File Snippet End Position gu+c7qe  
int nThreadID; //Thread's ID =NyN.^bwT  
boolean bDownOver = false; //Downing is over mQRQ2SN6  
boolean bStop = false; //Stop identical C -@  
FileAccessI fileAccessI = null; //File Access interface R[eQ}7;+  
Evd>s  
8 *@knkJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s1,kTde  
{ zWiM l.[  
this.sURL = sURL; *9"L?S(X#  
this.nStartPos = nStart; i ! wzID  
this.nEndPos = nEnd; =^. f)  
nThreadID = id; tw. 2h'D  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <ex,@{n4  
} 1:-^*  
K`!q1 g`  
!^Mk5E(  
public void run() SK2nxZOH  
{ TNs0^h)  
while(nStartPos < nEndPos && !bStop) xPa>-N=*  
{ JpVV0x/Q/_  
2ql7*g?Uq@  
B_FfXFQm<  
try{ f =H,BQ  
URL url = new URL(sURL); z7+y{-{Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ([loWr}QR  
httpConnection.setRequestProperty("User-Agent","NetFox"); !!Tk'=t9"3  
String sProperty = "bytes="+nStartPos+"-"; 0 S3~IeJ  
httpConnection.setRequestProperty("RANGE",sProperty); gi::?ET/.  
Utility.log(sProperty); \>0F{-cR$  
pdnkHR$  
Xg*IOhF6x  
InputStream input = httpConnection.getInputStream(); 4l! ^"=rh  
//logResponseHead(httpConnection); 3c5=>'^F  
ZyE2=w7n  
8Z;wF  
byte[] b = new byte[1024]; *G"vV>OSV  
int nRead; tAD{{GW9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {7^7)^@  
{ yteJHaq  
nStartPos += fileAccessI.write(b,0,nRead); 'jp nQcwxx  
//if(nThreadID == 1) w$J0/eX{A  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H-%)r&"vn  
} MF>1u%  
?>lvV+3^`  
u@SE)qg  
Utility.log("Thread " + nThreadID + " is over!"); Y21,!$4gb  
bDownOver = true; sY?pp '}a  
//nPos = fileAccessI.write (b,0,nRead); owA3>E5t&  
} 846j<fE  
catch(Exception e){e.printStackTrace ();} cnAwoTt4  
} 'U<-w$!f+^  
} mk JS_6  
&&e{9{R  
O@U[S.IK  
//打印回应的头信息 ?9qA"5  
public void logResponseHead(HttpURLConnection con) J~z;sTR  
{ EUdu"'=4a  
for(int i=1;;i++) 7+aTrE{  
{ "rz|sbj  
String header=con.getHeaderFieldKey(i); y}jX/Ln  
if(header!=null) Ba/Z<1)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H27J kZ&  
Utility.log(header+" : "+con.getHeaderField(header)); zuOx@T^  
else ?'H);ou-p  
break;  /kGRN @  
} ^n5[pF}Gw  
} M70Xdn  
;$W/le"Xr  
+O23@G?x  
public void splitterStop() O~F/pJN`  
{ T2# W=P  
bStop = true; gvYib`#  
} {t: ZMUV  
C)> ])'S  
gBRhO^Sz  
} )f4D2c&VE  
{N+N4*  
_H|c _  
/* zECdj'/  
**FileAccess.java =p>"PqJ/7n  
*//文件访问(定位,写) P/._ tQu6  
package NetFox; y|!%C-P  
import java.io.*; Xui${UYN  
gkS#=bv9e@  
c8mcJAc  
public class FileAccessI implements Serializable{ c_xtwdkL9  
=?UCtYN,P  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~~ ]/<d  
RandomAccessFile oSavedFile; WAiEINQ^)  
long nPos; }x4,a6^  
UM%[UyYQ  
2A@9jl s  
public FileAccessI() throws IOException dwks"5l  
{ tYyva  
this("",0); >jAr9Blz]  
} rAD5n, M]  
vrXmzq  
+]Of f^s  
public FileAccessI(String sName,long nPos) throws IOException POTW+Zq]  
{ .['@:}$1  
oSavedFile = new RandomAccessFile(sName,"rw"); }gL9G  
this.nPos = nPos; qOz,iR?}  
oSavedFile.seek(nPos); RsU=fe,  
} ")7,ZN;  
QOIi/flK  
l(9$s4R  
public synchronized int write(byte[] b,int nStart,int nLen) u4B,|_MK  
{ U7J0&  
int n = -1; }(O/y-  
try{ { 'Hi_b3  
oSavedFile.write(b,nStart,nLen); dz.]5R  
n = nLen; cs`/^2Vf"#  
} .z+?b8Q\  
catch(IOException e) R3F>"(P@tS  
{ %JDG aG'  
e.printStackTrace (); (utm+*V,  
} :7p0JGd  
~c[} %Ir>  
Pgg6(O9}B^  
return n; AY:3o3M  
} K|];fd U  
6cSMKbgZJ  
>]Hz-2b  
} H[V^wyi'z  
/ee:GjUkB  
S5d:?^PGg  
/* ^4]#Ri=U  
**SiteInfoBean.java sj2v*tFb  
*/ ([UuO}m-  
package NetFox; +Uq9C-Iu  
B{a:cz>0<  
MQE=8\  
public class SiteInfoBean { JU:!lyd  
dra'1E  
k);z}`7  
private String sSiteURL; //Site's URL y&9S+  
private String sFilePath; //Saved File's Path Ri4_zb  
private String sFileName; //Saved File's Name Gk,{{:M:5  
private int nSplitter; //Count of Splited Downloading File rB?u.jn0T  
Vj4 if@Z  
xPb;_~  
public SiteInfoBean() #`:s:bwM:  
{//nSplitter的缺省值为5 f2_LfbvH  
//default value of nSplitter is 5 +-'qI_xo  
this("","","",5); !$AVl MnJ  
} 7GfgW02  
"%urT/F v&  
lf0/ 0KH  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P~ _CDh.N  
{ PTA;a 0A  
sSiteURL= sURL; swG^L$r`  
sFilePath = sPath; >NB}Bc  
sFileName = sName; a\vf{2  
this.nSplitter = nSpiltter; <,Sy:>:"  
t2p/NIn  
r4JXbh6Tt  
}  g}Hk4+  
/`\-.S9  
0-0 )E&2  
public String getSSiteURL() 7E Y~5U/4  
{ A/{pG#if]3  
return sSiteURL; % %c0UaV  
} @ 5 kKMz  
!/< 5.9!9r  
, p1 (0i  
public void setSSiteURL(String value) =t@m:  
{ FvG9PPd  
sSiteURL = value; ?*}76u  
} Mn>dI@/gM  
Qu!\Cx@  
jm RYL("  
public String getSFilePath() R|V<2  
{ ol!o8M%Q  
return sFilePath; kSU5  }  
} 68FxM#xR  
bw%1*;n)  
+Jt"JJ>%k  
public void setSFilePath(String value)  =e$ #m;  
{ H xb{bF  
sFilePath = value; `Kym{og  
} UgJlXB|a%2  
]~WP;o  
&M>S$+I n  
public String getSFileName() hp-< 8Mf  
{ CSr{MF`]e  
return sFileName; YL){o$-N"J  
} 4Xz6JJ1U[H  
3 %DA{  
qu[w_1%S  
public void setSFileName(String value) ,;/4E  
{ W3<O+S&  
sFileName = value; u:HKmP;  
} rFx2 S  
ljiq+tT  
!ox&`  
public int getNSplitter() J3:P/n&  
{ /;OJ=x3i  
return nSplitter; 4 T^M@+&|  
} m9L+|r  
jb7=1OPD_  
g!~j Wn?A  
public void setNSplitter(int nCount) //J:p,AF  
{ rA1 gH6D  
nSplitter = nCount; A:D\!5=  
} $35Oyd3s<  
} @%#(Hse  
G x,D'H'  
]6:5<NW  
/* 8U;!1!+ 7)  
**Utility.java Ev^Xs6 }"  
*/ ZzKn,+  
package NetFox; `Mjm/9+18  
"Q/3]hc.  
y:,{U*49  
public class Utility { qHKZ5w  
_p_F v>>:  
92SB'T>  
public Utility() x _2]G'  
{ Q1jyetk~I  
ITsJjcYw  
&a|oJ'clz  
} yjSN;3t71  
@?1%*/  
//线程睡眠 ] !A;-m  
public static void sleep(int nSecond) *,R e&N8  
{ =?f}h{8x>  
try{ H!Od.$ZIX  
Thread.sleep(nSecond); cYp}$  
} $(NfHIX  
catch(Exception e) r[,KE.^6~#  
{ kl={L{r  
e.printStackTrace (); r]E$uq bR  
} q@\_q!  
} JJ+<?CeHD  
Y{O&- 5H^|  
//日志 g@U#Y#b@"  
public static void log(String sMsg) +p[~hM6?  
{ T2->  
System.err.println(sMsg); =3T?U_u@  
} _ 4W#6!  
:D,YR(])  
<VBw1|)$@  
public static void log(int sMsg) oby*.61?5l  
{ |`okIqp  
System.err.println(sMsg); \8$`:3,@  
} %*gO<U4L]  
} #<~f~{x  
y{"E) YY  
[x)e6p)  
/* dL\8^L  
**TestMethod.java {L=[1  
*/ J)G3Kq5>:b  
package NetFox; 9s!/yiP5  
"5YdmBy  
O`u!P\  
public class TestMethod { \fhT#/0N  
C1/jA>XW  
xHG oCFB  
public TestMethod() d"78:+  
{ ///xx/weblogic60b2_win.exe gfYB|VyWo  
try{ Qx6/Qa S?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v<SEGv-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KRtu@;?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); e ?YbG.(E9  
fileFetch.start(); 4yA`);r62  
} A!D:Kc3  
catch(Exception e){e.printStackTrace ();} ]Rye AJ3  
Z C93C7lJ  
j+9 S  
} @5wg'mM  
V\"5<>+O  
NM@An2  
public static void main(String[] args) sV<4^n7  
{ Q7r,5w& cm  
new TestMethod(); =5`@:!t7  
} `/zt&=`VB  
} 4I*Mc%dD  
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