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http断点续传简单实现(java)

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/* AK&S5F>D+B  
**SiteFileFetch.java fXXr+Mor  
*/ a#^B2  
package NetFox; sJ# 4(r`  
import java.io.*; /|r^W\DV&x  
import java.net.*; =7-9[{  
e8y;.D[2  
~hZ"2$(0  
public class SiteFileFetch extends Thread { d{rQzia"mV  
A3rPt&<a  
IN4=YrM^  
SiteInfoBean siteInfoBean = null; //文件信息Bean s4G|_==  
long[] nStartPos; //开始位置 A:>01ZJ5S+  
long[] nEndPos; //结束位置 cmBB[pk\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ^:K3vC[h;c  
long nFileLength; //文件长度 bsuus R9W  
boolean bFirst = true; //是否第一次取文件 So{x]x:f  
boolean bStop = false; //停止标志 'Hc-~l>D  
File tmpFile; //文件下载的临时信息 [r3!\HI7x  
DataOutputStream output; //输出到文件的输出流 -d8TD*^  
Q<z_/ j9  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,%n\=  
public SiteFileFetch(SiteInfoBean bean) throws IOException #?5 (o  
{ 8 ![|F:  
siteInfoBean = bean; ,O.3&Nz,c  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); CJ(NgYC h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0FGe=$vD  
if(tmpFile.exists ()) Uh.oErHQD  
{ y@ ML/9X8q  
bFirst = false; _Bj)r}~7#  
read_nPos(); pM x  
} | B. 0TdF  
else _=+V/=  
{ r9X?PA0f  
nStartPos = new long[bean.getNSplitter()]; Ae mDJ8Y  
nEndPos = new long[bean.getNSplitter()]; J+[_Wd  
} "nZ*{uv  
wyp|qIS;  
) u3 Zm  
0*%Z's\M"  
} iDMJicW!+F  
:r%P.60H X  
nNrPHNfqD  
public void run() ~ }F{vm  
{  =Qh\D  
//获得文件长度 NXwz$}}Pp  
//分割文件 W4hbK9y  
//实例FileSplitterFetch Z&0'a  
//启动FileSplitterFetch线程 N U|d  
//等待子线程返回 , 3,gG "  
try{ .^N/peU q  
if(bFirst) @[5xq  
{ Uh7v@YMC  
nFileLength = getFileSize(); =.y~fA!  
if(nFileLength == -1) D<|qaHB=  
{ e "/;7:J5\  
System.err.println("File Length is not known!"); ]x\-$~E  
} eK.e| z|  
else if(nFileLength == -2) j2Tr $gx<  
{ >"gf3rioW  
System.err.println("File is not access!"); W4[V}s5u  
} )A!>=2M `  
else (EK"V';   
{ OC1I&",Ai|  
for(int i=0;i<nStartPos.length;i++) u1t% (_h  
{ $SM# < @  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $tz;<M7B  
} )_{dWf1  
for(int i=0;i<nEndPos.length-1;i++) ulu9'ch  
{ /E Bo3`  
nEndPos = nStartPos[i+1]; 7w 37S  
} f:ZAG4B  
nEndPos[nEndPos.length-1] = nFileLength; ?g?L3vRK  
} )\sc83L  
} hy}8Aji&  
kjEEuEv  
_$= _du  
//启动子线程 .gG1kWA-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SGh1 DB  
for(int i=0;i<nStartPos.length;i++) [!}:KD2yX  
{ M>&%(4K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A:aE|v/T&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B+[A]dgS  
nStartPos,nEndPos,i); /GIxR6i  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^\\Tx*#i  
fileSplitterFetch.start(); GKvN* SU=  
} qY~`8 x  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =0^Ruh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HFwN  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BDVHol*g  
nEndPos = " + nFileLength); m-H-6`]  
// fileSplitterFetch[nPos.length-1].start(); 9;Itqe{8w  
Gqcq,_?gt  
!,[C] Q1  
//等待子线程结束 Vnx,5E&  
//int count = 0; ?"zY" *>4  
//是否结束while循环 RQ'exc2x0  
boolean breakWhile = false; 6:q"l\n>  
h.-@ F  
~.A)bp  
while(!bStop) Hu.t 3:w  
{ ]4h92\\965  
write_nPos(); SV:4GVf  
Utility.sleep(500); ox:[f9.5  
breakWhile = true; +x_Rfk$fb  
{.Z}5K  
5WC+guK7  
for(int i=0;i<nStartPos.length;i++) [|P!{?A43|  
{ SG-'R1 J  
if(!fileSplitterFetch.bDownOver) }:u~K;O87  
{ FL(6?8zK  
breakWhile = false; (S xR`QP?,  
break; vFE;D@bz:  
} ta`N8vnf  
} $-#Yl&?z9  
if(breakWhile) 58%#DX34M  
break; Q-MQ9'  
X>NhZ5\  
 1WY/6[  
//count++; OR}c)|1  
//if(count>4) 8<.C3m 6h  
// siteStop(); F;gx%[$GX  
} JNkwEZhHyg  
vhsk 0$f  
qw@puw@D  
System.err.println("文件下载结束!"); .pfP7weQ  
} C0S^h<iSe*  
catch(Exception e){e.printStackTrace ();} w"OP8KA:^T  
} L3 G \  
X@k`3X  
D[_|*9BC  
//获得文件长度 -8r  
public long getFileSize() ~><^'j[  
{ T:/,2.l  
int nFileLength = -1; 3 n'V\H vz  
try{ L]d-hs  
URL url = new URL(siteInfoBean.getSSiteURL()); ]Ar\c["  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D8>enum  
httpConnection.setRequestProperty("User-Agent","NetFox");  EI_  
@y82L8G/  
wY~&Q}U  
int responseCode=httpConnection.getResponseCode(); 1Ab>4UhD  
if(responseCode>=400) C8 vOE`U,J  
{ 4'-|UPhx  
processErrorCode(responseCode); OE4+GI.r-  
return -2; //-2 represent access is error ]8icBneA~'  
} |N}P(GF  
:JfE QIN  
DXa=|T  
String sHeader; 0 ;b[QRmy  
b&=5m  
6KVn nK  
for(int i=1;;i++) /ODXV`3QYI  
{ mp9{m`Jb*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +)j1.X  
//Utility.log(in.readLine()); h$.:Uj8/  
sHeader=httpConnection.getHeaderFieldKey(i); 9lGOWRxR)  
if(sHeader!=null) jM$`(Y  
{ 3G uH857ov  
if(sHeader.equals("Content-Length")) &}?$i7x5  
{ ;5tazBy&:C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zo[[>MA  
break; ^| /](  
} W?eu!wL#p  
} ~=KJzOS,S  
else 0pJ ":Q/2)  
break; MXzVgy  
} "y_#7K  
} [5uRS}!  
catch(IOException e){e.printStackTrace ();} A |3tI  
catch(Exception e){e.printStackTrace ();} G7)Fk%>  
p=C%Hmd5E  
m;D- u>o  
Utility.log(nFileLength); wKi^C 8Z2  
u1z  
mwY IJy[  
return nFileLength; J?Dq>%+ ^  
} K]j0_~3s  
,RgB$TcE  
:^Fh!br==  
//保存下载信息(文件指针位置) )ZBY* lk9  
private void write_nPos() YKE46q;J  
{ nK$X[KrV'  
try{ B*~5)}1op  
output = new DataOutputStream(new FileOutputStream(tmpFile)); *;m5'}jsy  
output.writeInt(nStartPos.length); :.?gHF.?  
for(int i=0;i<nStartPos.length;i++) om |"S  
{ 4<cz--g  
// output.writeLong(nPos); ?gPKcjgoH!  
output.writeLong(fileSplitterFetch.nStartPos); Q}!mx7b0]  
output.writeLong(fileSplitterFetch.nEndPos); $uap8nN  
} 5*E#*H  
output.close(); \MK*by  
} c\ia6[3sX  
catch(IOException e){e.printStackTrace ();} B9T!j]'  
catch(Exception e){e.printStackTrace ();} Rb%%?*|  
} cuK,X!O  
RPIyO  
,SQZD,3v4  
//读取保存的下载信息(文件指针位置) YKbaf(K )9  
private void read_nPos() P%#*-zCCx  
{ 'Fs)Rx}\0  
try{ KAsS [  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *1 G>YH  
int nCount = input.readInt(); GEEW?8  
nStartPos = new long[nCount]; uA$<\fnz  
nEndPos = new long[nCount]; m85WA # `  
for(int i=0;i<nStartPos.length;i++) ?x+Z)`w_  
{ =) E,8L  
nStartPos = input.readLong(); 6m VuyI  
nEndPos = input.readLong(); xGU(n _Y  
} Qc[3Fq,f  
input.close(); 8E8N6  
} !q-f9E4`  
catch(IOException e){e.printStackTrace ();} E;d7ch  
catch(Exception e){e.printStackTrace ();} @q"m5  
} 25NTIzI@@  
-F=v6N{  
@x eAc0.^  
private void processErrorCode(int nErrorCode) iA0q_( \X  
{ mo1oyQg8  
System.err.println("Error Code : " + nErrorCode); nOQa_G]Gz  
} zNY)'  
7T"XPV|W6  
rU;RGz6}  
//停止文件下载 r1<F  
public void siteStop() avy"r$v_&  
{ Ja SI^go  
bStop = true; dJv!Dts')C  
for(int i=0;i<nStartPos.length;i++) 'S2bp4G  
fileSplitterFetch.splitterStop(); K"u NxZ  
->h6j  
A].>.AI  
} })w*m  
} 7HVZZ!>~  
//负责部分文件的抓取 kGL1!=>  
**FileSplitterFetch.java a6:x"Tv  
*/ 7@6g<"I  
package NetFox; 'kYwz;gp  
.i^7|o:  
(mtoA#X1:h  
import java.io.*; s;1]tD  
import java.net.*; S,U Pl}KF  
/B5-Fx7j3  
t6BHGX{o  
public class FileSplitterFetch extends Thread { \`, [)`  
bsd99-_(4  
-!0_:m3  
String sURL; //File URL yQ3OL#  
long nStartPos; //File Snippet Start Position &QG6!`fK}3  
long nEndPos; //File Snippet End Position VdP`a(Yd;  
int nThreadID; //Thread's ID i/b'4o=8  
boolean bDownOver = false; //Downing is over XX1Il;1G#  
boolean bStop = false; //Stop identical Iyd?|f"  
FileAccessI fileAccessI = null; //File Access interface |ou b!fG4  
d*oUfiW  
DI`%zLDcY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,-+"^>  
{ a=XW[TY1  
this.sURL = sURL; hk/! 'd  
this.nStartPos = nStart; 1xU3#b&2tC  
this.nEndPos = nEnd; 6{ ,HiY  
nThreadID = id; SlSM+F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k|BHnj  
} vA)O {W\o  
k8,?hX:  
s/:Fwr4q#a  
public void run() *cTO7$\[  
{ 8 4i_k  
while(nStartPos < nEndPos && !bStop) 3+J0!FVla  
{ v|ox!0:#  
w'X]M#Q><  
oo=#XZkk  
try{ *_ +7ni  
URL url = new URL(sURL); Gn)y> AN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =&!HwOnp  
httpConnection.setRequestProperty("User-Agent","NetFox"); tA$)cg+.  
String sProperty = "bytes="+nStartPos+"-"; ~^ ^ NHq  
httpConnection.setRequestProperty("RANGE",sProperty); .)|a2d ~F  
Utility.log(sProperty); G pbC M~x  
cECi')  
jKZt~I  
InputStream input = httpConnection.getInputStream(); Y F:2>w<  
//logResponseHead(httpConnection); h;V,n  
w[_x(Ojq;  
=SD\Q!fA  
byte[] b = new byte[1024]; \<vNVz7.D  
int nRead; fbFX4?-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) - O"i3>C  
{ yAL1O94  
nStartPos += fileAccessI.write(b,0,nRead); ]NhS=3*i+  
//if(nThreadID == 1) aS|wpm)K>8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^). )  
} D;Gq)]O  
OzT#1T1'c  
Dml*T(WM>  
Utility.log("Thread " + nThreadID + " is over!"); {F N;'Uc  
bDownOver = true; iqhOi|!  
//nPos = fileAccessI.write (b,0,nRead); G5D2oQa=8  
} CK_(b"  
catch(Exception e){e.printStackTrace ();} * n(> ^  
} pium$4l2#  
} xt4)Ya  
fag^7rz  
7n)&FX K`  
//打印回应的头信息 uhV0J97  
public void logResponseHead(HttpURLConnection con) XYx 6V  
{ wFlvi=n/  
for(int i=1;;i++) NZu)j["  
{ j<pw\k{i  
String header=con.getHeaderFieldKey(i); _,6f#t  
if(header!=null) ,}xbAA#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I8H%=Kb?9  
Utility.log(header+" : "+con.getHeaderField(header)); IMQ]1uq0$  
else dSIH9D  
break; U,1AfzlF  
} HNa]H;-+5  
} NYABmI/0c  
Ip}Vb6}  
9umGIQHnil  
public void splitterStop() rOD1_X-  
{ _SZ5P>GIU  
bStop = true; gQ~5M'#  
} g8ES8S M  
rZbEvS  
%Y4e9T".  
} ">dq0gD  
U},=LsDsW4  
I~'*$l  
/* ZX b}91rzt  
**FileAccess.java -Uo?WXP]B'  
*//文件访问(定位,写) o@lWBfB*%e  
package NetFox; 1u]P4Gf=  
import java.io.*; p4VqV6LwD  
LF*Q!  
1xnLB>jP#  
public class FileAccessI implements Serializable{ d0 er^ ~  
%up}p/?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;52'}%5  
RandomAccessFile oSavedFile; Jf:,y~mV  
long nPos; 2aNT#J"_  
F5gObIJtuY  
Jx-wO/  
public FileAccessI() throws IOException W VkR56  
{ iO!6}yJ*V  
this("",0); ++[5q+b  
} (L6Cy% KgV  
y[0`hSQ)~  
j<tq1?? [b  
public FileAccessI(String sName,long nPos) throws IOException N~=A  
{ [A~G-  
oSavedFile = new RandomAccessFile(sName,"rw"); icUT<@0  
this.nPos = nPos; *QE<zt  
oSavedFile.seek(nPos); Z& !!]"I  
} j?(!^ _!m  
0? bA$y  
9w;?-  
public synchronized int write(byte[] b,int nStart,int nLen) 5b #QYu  
{ us)*2`?6t  
int n = -1; H5wb_yBQ+  
try{ J/D|4fC  
oSavedFile.write(b,nStart,nLen); ),@f6](  
n = nLen; wpPn}[a  
} `T!#@&+  
catch(IOException e) sLcY,AH  
{ Y'"N"$n'_  
e.printStackTrace (); +1{fzb>9_  
} ;Fl<v@9  
cep$_J a  
~waNPjPRG  
return n; M<8ML!N0;t  
} )JgC$ <  
|qjZ38;6  
#I\Y= XCY  
} R U!?-#*  
PE@+w#i7*  
7h<> k*E)  
/* 32XS`Z  
**SiteInfoBean.java ^nDal':*  
*/ 6`nR5fh  
package NetFox;  #ch  
}HZ{(?  
5vZ#b\;#V  
public class SiteInfoBean { EO"C8z'al  
p6 xPheD  
v"1Po_`  
private String sSiteURL; //Site's URL =fG:A(v%}  
private String sFilePath; //Saved File's Path g@nk.aRw  
private String sFileName; //Saved File's Name 3 (lVmfk  
private int nSplitter; //Count of Splited Downloading File IS_Su;w>4  
Q .RO  
"G?9b  
public SiteInfoBean() oh}^?p  
{//nSplitter的缺省值为5 - @bp4Z=  
//default value of nSplitter is 5 a5wDm  
this("","","",5); M'jXve(=yF  
} Q</h-skLZ  
E8[XG2ye  
+g\;bLT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o'UHStk  
{ ubGs/Vzye  
sSiteURL= sURL; cx(2jk}6  
sFilePath = sPath; LM,fwAX  
sFileName = sName; !*a[jhx  
this.nSplitter = nSpiltter; [e4![G&y`  
6$ e]i|e  
(r F?If  
} d /j@_3'  
5:gj&jt;)7  
QUP|FIpZ  
public String getSSiteURL() _PB@kH#  
{ obGWxI%a  
return sSiteURL; wGXwzU  
} wJIB$3OT  
Ph)| j&]  
6v47 QW|'  
public void setSSiteURL(String value) Di.;<v#FL  
{ o~~9!\  
sSiteURL = value; \graMu}-  
}  5H.Db  
%x2b0L\g  
)/%S=c  
public String getSFilePath() 84`rbL!M  
{ W^R'@  
return sFilePath; ba&o;BLUy  
} BlaJl[Piv  
B7 c[ 4  
.Ty,_3+{#p  
public void setSFilePath(String value) Vipp /WV  
{ ~%P3Pp  
sFilePath = value; e[4V%h  
} Yo'K pdn  
(T;9us0  
1ih*gJPpj  
public String getSFileName() R+Lk~X^*l'  
{ >l2w::l%  
return sFileName; 5P\N"Yjx'  
} _;G=G5r  
iwo$\  
~07RFR  
public void setSFileName(String value) NhDA7z`b'J  
{ 4K,''7N3  
sFileName = value; #WEq-0L   
} *gSO&O=  
.eTk=i[N-  
okDJ(AIV+  
public int getNSplitter() wP`sXPSmIu  
{  coAW9=o}  
return nSplitter; eBvW#Hzp  
} kH2oK:lN  
m<FK;   
[d:@1yc  
public void setNSplitter(int nCount) 4WG=m}X  
{ #Q+R%p  
nSplitter = nCount; 0x#E4v (UA  
} 5mIXyg 0:  
} sY^lQN  
Bm<^rhJ9  
9l l|JeNi  
/* J0qXtr%h\  
**Utility.java V/&o]b   
*/ /s8/q2:  
package NetFox; MCd F!{  
i* gKtjx  
"aA_(Ydzj  
public class Utility { Xq%*# )M;  
O\JD,w  
{9;eH'e  
public Utility() >]?Jrs  
{ U#"WrWj  
TU-c9"7M~  
MA"#rOcP  
} nrbazyKm  
2:~cJk{  
//线程睡眠 /=ACdJ  
public static void sleep(int nSecond) Wxk; g  
{ *#GDi'0  
try{ ?&\h;11T  
Thread.sleep(nSecond); U%,;N\:_  
}  Q>[Ce3  
catch(Exception e) DUo0w f#D^  
{ N*':U^/t4J  
e.printStackTrace (); wO!% q[  
} >F|qb*Tm7  
} d/4ubf+$k  
)^(P@D.L  
//日志 6d};|#}  
public static void log(String sMsg) k%!VP=c4s  
{ :@;6  
System.err.println(sMsg); IO6MK&R  
} #AvEH=:  
%A=|'6)k2  
QSv^l-<  
public static void log(int sMsg) lT3|D?sF  
{ 5Abz 5-^KH  
System.err.println(sMsg); l\Cu1r-z  
} c+wuC,  
} WN1Jm:5YV  
>F~ITk5`Oo  
 kMqD iJ  
/* H8sK}1.  
**TestMethod.java ,b4~!V  
*/ MyqiBGTb  
package NetFox; XUf7yD  
S_j1=6 #^  
IY0 3"  
public class TestMethod { >mew"0Q  
KZZOi:  
bu_/R~&3{  
public TestMethod() YV4 : 8At1  
{ ///xx/weblogic60b2_win.exe MN\i-vAL8  
try{ PRZ8X{h  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B3eNFS  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *b:u * `@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); e$H|MdYIA  
fileFetch.start(); q _19&;&  
} Yu1QcFuy  
catch(Exception e){e.printStackTrace ();} cNx \&vpd  
i<J^:7  
gh'kUZG a  
} xSdN5RN  
K_Z+]]$#  
Z~:/#?/  
public static void main(String[] args) p8$\uo9YQ  
{ :|zp8|  
new TestMethod(); ~K_]N/ >  
} {[my"n 2  
} CH55K[{<  
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