http断点续传简单实现（java)

/* OI@;ffHSW  
**SiteFileFetch.java 3Ryae/Nk  
*/ #2dd`F8  
package NetFox; etcpto=Mo  
import java.io.*; BQ[,(T`+R  
import java.net.*; E~[v.3`  
z8MKGM  
}&E'o
x<S  
public class SiteFileFetch extends Thread { ]]R!MnU:$  
@<^_ _."  
qD#E, "%  
SiteInfoBean siteInfoBean = null; //文件信息Bean h;s~I/e(  
long[] nStartPos; //开始位置 Mk:k0,z  
long[] nEndPos; //结束位置 ceKR?%8s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 APne!  
long nFileLength; //文件长度 p3e_:5k  
boolean bFirst = true; //是否第一次取文件 n]K`ofjl^  
boolean bStop = false; //停止标志 \J)ffEK
Ip  
File tmpFile; //文件下载的临时信息 A2C|YmHk  
DataOutputStream output; //输出到文件的输出流 0 It[Pa qG  
D%WgE&wtM  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） XIS.0]~  
public SiteFileFetch(SiteInfoBean bean) throws IOException '4T]=s~N  
{ V~9vf*X  
siteInfoBean = bean; QTy xx  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /o/0 9K  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ">-mZ'$#L  
if(tmpFile.exists ()) :J 7p=sX  
{ ?PpGBm2f*  
bFirst = false; <Z0N)0|  
read_nPos(); $qvk9 B0E  
} =|Q7k+b  
else F:3*i^ L  
{ RV%aFI )  
nStartPos = new long[bean.getNSplitter()]; :!fP~(R'm  
nEndPos = new long[bean.getNSplitter()]; 49e~/YY  
} _0ra
zNk  
o%~PWA*Qp  
Nt>wzPd)  
sKIpL(_I$  
} 2r0u[  
KS9eV  
rM{3
]v{~  
public void run() v/1&V+"^kd  
{ ^GS,4[)H  
//获得文件长度 %-A#7\  
//分割文件 {}Q A#:V  
//实例FileSplitterFetch BAJEn6f?  
//启动FileSplitterFetch线程 *[@k=!73  
//等待子线程返回 y*f5_  
try{ Q?1' JF!G  
if(bFirst) `S&$y4|Vs  
{ |Z"5zL10  
nFileLength = getFileSize(); <`rl[C{  
if(nFileLength == -1) r )pg9}+  
{ xs'vd:l.Pp  
System.err.println("File Length is not known!"); N:_U2[V^d  
} !yfQ^a_
O  
else if(nFileLength == -2) c)7i%RF'  
{ >$%rsc}^  
System.err.println("File is not access!"); Os9;;^k  
} &*w)/W  
else 7yp}*b{s  
{ e>GX]tK  
for(int i=0;i<nStartPos.length;i++) QcXqMx  
{ ,hggmzA~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Sz"rp9x+  
} f0<'IgN  
for(int i=0;i<nEndPos.length-1;i++) x|TLMu=3=  
{ {[i 37DN  
nEndPos = nStartPos[i+1]; fw[Z7`\Q5  
} _@U11|  
nEndPos[nEndPos.length-1] = nFileLength; 8M"0o}wx  
} ?6m6 4{M  
} |q( .j4[i  
[r)Hm/_=|U  
0_A|K>7  
//启动子线程 oD@~wcMIT0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o1dECLQa  
for(int i=0;i<nStartPos.length;i++) vz~QR i*  
{ 1TuN  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pOe"S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j;3hQOl  
nStartPos,nEndPos,i); )`*=P}D  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u>YC4&  
fileSplitterFetch.start(); Cq<a|t  
} a$7}41F[~s  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9:]w|lE:D  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZQ0R3=52r  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", App9um3:  
nEndPos = " + nFileLength); Kgb3>r  
// fileSplitterFetch[nPos.length-1].start(); e*zt;SR  
|k3^ eeLk  
`<3/k  
//等待子线程结束 sfN6ro  
//int count = 0; V>Zw" #Q  
//是否结束while循环 H J8rb  
boolean breakWhile = false; A<+veqb4  
G(;C~kHX  
6oQSXB@  
while(!bStop) -=+@/@nV  
{ E\X:VQ9  
write_nPos(); 1&wI*4  
Utility.sleep(500); >7fNxQ  
breakWhile = true; ~0^d-,ZD5  
U)3*7D  
ly8IrgtKy  
for(int i=0;i<nStartPos.length;i++) ;mi+[`E  
{ Oh|KbM*vS  
if(!fileSplitterFetch.bDownOver) =:5o"g  
{ 1U/ dc.x5  
breakWhile = false; &2,0?ra2&  
break; g aq"+@fH  
} -q8R'?z[  
} y|e@zf  
if(breakWhile) Pf4b/w/  
break; wB~5&:]jr  
tr<iFT}C  
XITh_S4fs=  
//count++; qkg`4'rLg  
//if(count>4) 1 po.Cmx  
// siteStop(); t}!Y}D  
} {zri6P+s  
XEB1%. p  
'H]&$AZ;@
 
System.err.println("文件下载结束！"); #7Pnw.s3zz  
} q\`0'Z,  
catch(Exception e){e.printStackTrace ();} >7[o=!^:4  
} {Y(#<UDM  
Q8~|0X\
.g  
%:DH_0  
//获得文件长度 S%sD#0l  
public long getFileSize() E;m-^dxc  
{ Ow@}6&1  
int nFileLength = -1; }1sFddGVt  
try{ '&OJ hLE  
URL url = new URL(siteInfoBean.getSSiteURL()); T
rEo5H;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hk
v4^|  
httpConnection.setRequestProperty("User-Agent","NetFox"); .wb[cCUQ  
S]O0zv^}  
$BPTk0Y  
int responseCode=httpConnection.getResponseCode(); lDV}vuM<4  
if(responseCode>=400) {?zBc E:  
{ ZSUbPz  
processErrorCode(responseCode); ?q%&"  
return -2; //-2 represent access is error [T<Z?  
} $$tFP"pZ  
d<@SRHP(  
2#1G)XI  
String sHeader; ^_Ap?zn  
w`Ss MI  
s9p~  
for(int i=1;;i++) k\NwH?ppu  
{ mbS`+)1=l  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q9^6A90  
//Utility.log(in.readLine()); JJ+A+sfdk  
sHeader=httpConnection.getHeaderFieldKey(i); $ncJc  
if(sHeader!=null) ptlcG9d-  
{ s[}4Q|s%  
if(sHeader.equals("Content-Length")) .EXe3!J)!  
{ K!\$MBI  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V?0Yzg$sy  
break; }=fVO<Rv  
} Wt,t5  
} 1e'Ez4*  
else /
M3UK  
break; :Nt_LsH  
} TJhzyJ
"t  
} X;vfbF   
catch(IOException e){e.printStackTrace ();} .Z0$KQ'iy  
catch(Exception e){e.printStackTrace ();} a*g7uaoP  
{j!jm5  
?e. Ge0&  
Utility.log(nFileLength); 1>pFUf|cV  
43HZ)3!me  
8F;f&&L"y  
return nFileLength; yG ,oSp|  
} b;O@|HK&~  
x&N!SU6  
CU7WK}2h2C  
//保存下载信息（文件指针位置） _^(}6o  
private void write_nPos() ,+Bp>=pvs  
{ !SxZN dv  
try{ [l7 G9T}/[  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \d&/,?,Ey  
output.writeInt(nStartPos.length); Ny6 daf3f  
for(int i=0;i<nStartPos.length;i++) t V:oBT*  
{ xyvG+K&  
// output.writeLong(nPos); 4uV,$/  
output.writeLong(fileSplitterFetch.nStartPos); M`=bJO:  
output.writeLong(fileSplitterFetch.nEndPos); [JzOsi~R  
} 5{esL4k  
output.close(); #@v$`Df<  
} 0)^$9Z  
catch(IOException e){e.printStackTrace ();} G8Qo]E9-/  
catch(Exception e){e.printStackTrace ();} !idQ-&  
} (3[Lz+W.u  
Z{".(?+}1  
?L'4*S]  
//读取保存的下载信息（文件指针位置） V|njgcn d  
private void read_nPos() iL](w3EM  
{ #zL0P>P'a  
try{ N;6@f*3_i  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /ad]p
dF  
int nCount = input.readInt(); *}n)KK7aT  
nStartPos = new long[nCount]; @S>$y5if  
nEndPos = new long[nCount]; )dM
Xn2O  
for(int i=0;i<nStartPos.length;i++) wBbJ \  
{ rF*L@HI  
nStartPos = input.readLong(); D|lm,  
nEndPos = input.readLong(); S7A[HG;  
} )=:gO`"D  
input.close(); 8!!iwmH{  
} M.(shIu!+  
catch(IOException e){e.printStackTrace ();} -2\%?A6L  
catch(Exception e){e.printStackTrace ();} j0]|$p  
} /;K?Y#mf~j  
fho$:S  
>JWW2<  
private void processErrorCode(int nErrorCode) UojHlTg#bT  
{ f5droys9  
System.err.println("Error Code : " + nErrorCode); -eA3o2'  
} |K jy4.2  
aV6l"A]  
M10u?  
//停止文件下载 mK);NvJ!  
public void siteStop() JBCJVWUt  
{ )}KQtkU8:  
bStop = true; \B$Q%\-PX  
for(int i=0;i<nStartPos.length;i++) -$8M#n,  
fileSplitterFetch.splitterStop(); +~H mP
Q  
' >
F_y t9  
.AzGPcJY  
} 5V($|3PI  
} /P8`)?f~y  
//负责部分文件的抓取 DOzJ-uww1  
**FileSplitterFetch.java #G/ _FRo`  
*/ k\~A\UIYo  
package NetFox; S(b5Gj
/Kd  
OGC|elSM  
|iJ+e -_R  
import java.io.*; !8#!P  
import java.net.*; POouO/r$  
`B4Px|3  
x9Qa.Jmj  
public class FileSplitterFetch extends Thread { #3L=\j[ y  
G]T A7~VT  
cHG>iW9C  
String sURL; //File URL ti)4J2c,8  
long nStartPos; //File Snippet Start Position bN',-[E  
long nEndPos; //File Snippet End Position .).*6{_  
int nThreadID; //Thread's ID !N::1c@C  
boolean bDownOver = false; //Downing is over 3XeCaq'N  
boolean bStop = false; //Stop identical %~ROV>&  
FileAccessI fileAccessI = null; //File Access interface ST^@7f_  
d:x=g i!  
}&o*ZY-1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "E><:_,\  
{ t\p_QWnF  
this.sURL = sURL; !{L6 4qI  
this.nStartPos = nStart; dE_I=v  
this.nEndPos = nEnd; DJF-J#  
nThreadID = id; OcB
n1k.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r$7D;>*O{  
} c20'{kH  
Hsoe?kUHF  
o#IQz_  
public void run() SLiQHWw*J  
{ b,7@)sZ*  
while(nStartPos < nEndPos && !bStop) 9=-!~_'1-  
{ @+S5"W  
|0wUOs*5  
l*l(QvN_  
try{ [P*w$Hn  
URL url = new URL(sURL); h2Pvj37  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bN#)F    
httpConnection.setRequestProperty("User-Agent","NetFox"); I'_.U]An  
String sProperty = "bytes="+nStartPos+"-"; cE*Gd^  
httpConnection.setRequestProperty("RANGE",sProperty); & q(D90w.  
Utility.log(sProperty); Q\>Kd N{  
p:,(r{*?  
$g|/.XH%  
InputStream input = httpConnection.getInputStream(); vk:m>?(  
//logResponseHead(httpConnection); U73{Uv  
{FavF 9O  
Tk'YpL#U  
byte[] b = new byte[1024]; IX /r  
int nRead; \\qw"w9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n{~Ws^d  
{ Y^?J3[@  
nStartPos += fileAccessI.write(b,0,nRead); w:}RS.AK  
//if(nThreadID == 1) tXocGM{6C  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iCouGd}  
}
=;1MpD  
olC@nQ1c*  
>D';i\2j&  
Utility.log("Thread " + nThreadID + " is over!"); #nL&x3  
bDownOver = true; wHQyMq^  
//nPos = fileAccessI.write (b,0,nRead); |<@X* #X5  
} ZW}0{8Dk  
catch(Exception e){e.printStackTrace ();} Vm1U00lM{  
} T1@]:`&  
} YdgaZJs  
LWb5C{  
T/^ /U6JB  
//打印回应的头信息 V9 pKbX  
public void logResponseHead(HttpURLConnection con) v:YW[THre  
{ ]hBp elKJ  
for(int i=1;;i++) nnU &R  
{ B=:7N;BT  
String header=con.getHeaderFieldKey(i); cD6$C31Y]  
if(header!=null) ]JeA29  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lW,rzJ1  
Utility.log(header+" : "+con.getHeaderField(header)); i%+p\eeq*  
else y@|gG&f T  
break; =$B:i>z<  
} -P09
u82  
} =NH p%|  
0ih=<@1K  
o)P'H"Ki  
public void splitterStop() #^- U|~,  
{ gE/O29Y  
bStop = true; e+z_Rj%Y;I  
} iBy:HH  
]-$0?/`p8  
+oY[uF  
} oEE*H2l\  
!\a'GO[  
9HlRf6S  
/* F*F U[5  
**FileAccess.java /5@V $c8  
*//文件访问(定位，写) :QnN7&j|(w  
package NetFox; ?~e 8:/@  
import java.io.*; _|x b)_  
9=D\xBd|w  
r/E;tm[\  
public class FileAccessI implements Serializable{ m<>3GF,5bP  
2$^n@<uZ@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s%nx8"  
RandomAccessFile oSavedFile; 8_MR7'C1hi  
long nPos; y>vr Uxgo  
:XK.A   
nf5Ld"|%9  
public FileAccessI() throws IOException V`V Z[  
{ k0{5)Su"xr  
this("",0); *5k" v"NM(  
} ZM/*cA!"  
n|vIo)  
-X~VXeg  
public FileAccessI(String sName,long nPos) throws IOException I3QK~ V*j)  
{ T`f6`1x  
oSavedFile = new RandomAccessFile(sName,"rw"); nV-A0"z_&  
this.nPos = nPos; W6t"n_%?"  
oSavedFile.seek(nPos); >!|Hns  
} wRL=9/5(8  
0/d+26lR  
33lD`4i+  
public synchronized int write(byte[] b,int nStart,int nLen) <wge_3W#  
{ ~3Y)o|D3  
int n = -1; UdmYS3zs  
try{ YFD'&N,sx  
oSavedFile.write(b,nStart,nLen);
7z'l}*FRD  
n = nLen; K.?~@5%  
} ve2GRTO^aC  
catch(IOException e) f%0^89)  
{ ,[}5@cS  
e.printStackTrace (); @Iz vObK  
} MP\$_;&xB  
I"4j152P|  
" d3pkY  
return n; |:SBkM,  
} O1pBr=+j+{  
C`c;I7  
GwHMXtj4  
} $\l7aA5~  
TTaSg\K  
9^Q:l0|  
/* *a*\E R  
**SiteInfoBean.java E%\jR  
*/ _D:#M  
package NetFox; Z-`j)3Y  
=.,]}  
c#M'Mye  
public class SiteInfoBean { (.,`<rXw  
cQ~}qE>I  
Be+CV">2  
private String sSiteURL; //Site's URL $E@L{5Yt  
private String sFilePath; //Saved File's Path |'WaBy1  
private String sFileName; //Saved File's Name [Q&{#%M  
private int nSplitter; //Count of Splited Downloading File N"MuAUB:K  
pqO}=*v@  
2Q`@lTUv  
public SiteInfoBean() _4iTP$7[  
{//nSplitter的缺省值为5 %-!ruc"}  
//default value of nSplitter is 5 TSXa#
SKp  
this("","","",5); |?6r
&bT  
} Ml)~%ZbF  
'awL!P--  
/w0l7N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O;c;>x_dA  
{ Ym+k \h  
sSiteURL= sURL; mRB-}  
sFilePath = sPath; ^'Wkb7L  
sFileName = sName; n<6p0w  
this.nSplitter = nSpiltter; 1J<Wth{  
A6Ttx{]  
v]|^.x:  
} 9E^IEwq'  
`f`\j -Lu  
_y&m4Vuu  
public String getSSiteURL() !4cR&@[  
{ E\Hhi.-  
return sSiteURL; {"l_x]q  
} R,CFU l7Q  
L6yRN>5aE  
ucQ2/B#'4l  
public void setSSiteURL(String value) Mw2?U>h1  
{ -M}#-qwf  
sSiteURL = value; ;u!qu$O  
} 0Qvbc}KP8  
;:Q 5?zM  
PLR[nB7K  
public String getSFilePath() E+Z//)1Z  
{ hW[/{2<@  
return sFilePath; i8pM,Ppi~  
} O1IR+"0  
=M^4T?{T  
4jefU}e9#  
public void setSFilePath(String value) Reca5r1O  
{ zK
893)  
sFilePath = value; So?SBh1C  
} |>a sGP  
$wUFHEl  
N%!8I  
public String getSFileName() mh;<lW\K/Z  
{ b[,J-/;JNL  
return sFileName; .VN"j  
} )O~LXK=b  
Iih~W&  
v'0A$`w`  
public void setSFileName(String value) Ovh  
{ z?`&HU Nf  
sFileName = value; >oi`%V  
} {#N](yUm  
#UL:#pY  
22S4q`j  
public int getNSplitter() An cmSi  
{ $6.CN#  
return nSplitter; 8B;wn<O  
} H%NIdgo}  
nPh5(&E  
w1B!z  
public void setNSplitter(int nCount) :&ir5xHS  
{ V8ka*VJ(B  
nSplitter = nCount; 'EoJo9p6}  
} :4s{?IY
)l  
} :GXiA  
?.E6Ube  
^6s<  
/* )8vz4e Y  
**Utility.java @Z> {/  
*/ ]TQ2PVN2  
package NetFox; v'uWmL7C  
ve[` 0  
xrDHXqH  
public class Utility { S4uX utd  
=#]^H c  
<EFA^,3t%  
public Utility() ,K=\Y9l3  
{ 8px@sXI*`  
,>lOmyh  
j\& `  
} *4#)or  
,.[T]37  
//线程睡眠 $Kgw6  
public static void sleep(int nSecond) S~L$sqt  
{ rC.z772y%  
try{ {/`iZzPg  
Thread.sleep(nSecond); I$!rNfrs  
} zhtNL_  
catch(Exception e) +-YMW;5  
{ 7/QQ&7+NkS  
e.printStackTrace (); 9I>qD  
} 9qS~-'&q#  
} }&A!h  
$5kb3x<W  
//日志 DXu915  
public static void log(String sMsg) <uZ r.X  
{ vw VeHjR  
System.err.println(sMsg); @\0U`*]^)  
} 0`%eP5  
\M0-$&[+Z  
P34UD:  
public static void log(int sMsg) 7(cRm$)L  
{ 1!_$HA  
System.err.println(sMsg); [.Vy  
} Z5iP1/&D  
} |O3wAxc3W  
9jq}`$S{  
+bpUb0.W  
/* D/QSC]"  
**TestMethod.java >d-By  
*/ ("07t/||  
package NetFox; R6l`IlG`  
A;ip V :)  
ZDEz&{3U;  
public class TestMethod { =@(&xfTC  
J%ng8v5ex  
JDPn   
public TestMethod() V45A>#?U  
{ ///xx/weblogic60b2_win.exe 87WIDr  
try{ ..BIoSrj  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FOJ-?s(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ybLl[K(D=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2F*spu  
fileFetch.start(); 278:5yC  
} kN(*.Q|VZ  
catch(Exception e){e.printStackTrace ();} o2M+=O@  
~ 8L]!OQ9=  
T DOOq;+  
} k4:$LFw@  
iUDNm|e  
U-~cVk+LI  
public static void main(String[] args) 52S
q;X  
{ N$>.V7H&  
new TestMethod(); $yxwB/O(  
} &V/n!|q<H  
} vbEAd)*S  
点击下载更多相关资料