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http断点续传简单实现(java)

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/* :YUQKy  
**SiteFileFetch.java !g2 ~|G  
*/ LQ{z}Ay  
package NetFox; qgkC)  
import java.io.*; g+pj1ycw/  
import java.net.*; ,b'QL6>`  
)2&y;{]  
%|o2d&i  
public class SiteFileFetch extends Thread { ~&%&Z  
LEJn 1  
O <#H5/Tq  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8h$f6JE  
long[] nStartPos; //开始位置 j1i<.,0g  
long[] nEndPos; //结束位置 &Ndq ^!e  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 e"^n^_9  
long nFileLength; //文件长度 `&/~%>  
boolean bFirst = true; //是否第一次取文件 ~fz9AhU8  
boolean bStop = false; //停止标志 ^b&U0k$R  
File tmpFile; //文件下载的临时信息 Rdj/n :  
DataOutputStream output; //输出到文件的输出流 }pOJM &I  
qu+Zl1~$]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) SUaXm#9  
public SiteFileFetch(SiteInfoBean bean) throws IOException A[8vD</}_  
{ c 0.? d]  
siteInfoBean = bean; !McRtxq?~  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Scz/2vNi`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z_WJgH2c  
if(tmpFile.exists ()) XM:Y(#?l  
{ q6AL}9]9  
bFirst = false; )Q)H!yin  
read_nPos(); yN:U"]glC  
} ]MaD7q>+R  
else .3:s4=(f  
{ ~0T,_N  
nStartPos = new long[bean.getNSplitter()]; ,cwjieM  
nEndPos = new long[bean.getNSplitter()]; +WfO2V.  
} 9`|~- b  
x2$Y"b?vz  
MgrJ ;?L  
4) z*Vux  
} 5169E*  
#4wia%}u  
 r NT>{  
public void run() !Jk|ha~r  
{ Wo, "$Z6B  
//获得文件长度 y%@C-:  
//分割文件 ;pVnBi  
//实例FileSplitterFetch p)YI8nW  
//启动FileSplitterFetch线程 .u^4vVz  
//等待子线程返回 Cw,;>>Y_b<  
try{ .NRSBk  
if(bFirst) mY0FewwTy  
{ *]+5T-R% $  
nFileLength = getFileSize(); "[Hn G(gA  
if(nFileLength == -1) x2.YEuSMC  
{ yl UkVr   
System.err.println("File Length is not known!"); }e8u p*#me  
} l<dtc[  
else if(nFileLength == -2) ]h 4r@L3  
{ Q'R*a(pm  
System.err.println("File is not access!"); K/IG6s;Xj  
} p$!Q?&AV/  
else P>[,,w  
{ c^ W \0  
for(int i=0;i<nStartPos.length;i++) HWOOw&^<  
{ x/,(G~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Gcp!"y=i  
} "D[/o8Hk  
for(int i=0;i<nEndPos.length-1;i++) CoTe$C7  
{ |\6Ff/O  
nEndPos = nStartPos[i+1]; zwJK|Sk  
} NsUP0B}.  
nEndPos[nEndPos.length-1] = nFileLength; Lf0Wc'9{  
} E`gUNAKQ  
} -0:Equ?pz  
Eq/oq\(/6  
4#Id0['  
//启动子线程 gf^XqTLs  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u~\l~v^mj  
for(int i=0;i<nStartPos.length;i++) @; 0t+  
{ ~xakz BE  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1b`WzoJgH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M#o'hc  
nStartPos,nEndPos,i); :~4 M9  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .xV^%e?H  
fileSplitterFetch.start(); 3.E3}Jz`  
} fUa[3)I  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4elA<<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Jx3fS2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o~tL;(sz  
nEndPos = " + nFileLength);  >Q% FW  
// fileSplitterFetch[nPos.length-1].start(); ^Y?Y5`! Q  
Ew>lk9La(  
$4u8"ne)  
//等待子线程结束 =+"=|cQ  
//int count = 0; K3-Cuku  
//是否结束while循环 AroYDR,3+  
boolean breakWhile = false; |Wz`#<t  
*e%(J$t  
Gf\u%S!%  
while(!bStop) X(dHh O  
{ 6 TSC7jO  
write_nPos(); +_v#V9?  
Utility.sleep(500); qJq!0F  
breakWhile = true; <EM'|IR?  
2{I+H'w8:  
rUWC=?Q  
for(int i=0;i<nStartPos.length;i++) ^<w3i?KPW  
{ 'Z 82+uU%  
if(!fileSplitterFetch.bDownOver) Vk?US&1q}  
{ IZ 3e:  
breakWhile = false; zelM}/d  
break; *Vr;rk  
} ) ={ H  
} +~f5dJyk`  
if(breakWhile) 1YJ@9*l  
break; E)]RQ~jY?  
>@uFye$  
1,Ji|&Pwf  
//count++; ,;~@t:!c  
//if(count>4) E%vT(Kz  
// siteStop(); I W5N^J  
} Dx>~^ ^<  
*28:|blbL  
2'5u}G9  
System.err.println("文件下载结束!"); +?bjP6w_g  
} z,IUCNgM  
catch(Exception e){e.printStackTrace ();} WNWtQ2]  
} &LDA=B  
&7Lg) PG  
|tdsg  
//获得文件长度 H#FH '@J  
public long getFileSize() "HrZv+{  
{ .qD=u1{p9  
int nFileLength = -1; xay~fD  
try{ Ae|bAyAK  
URL url = new URL(siteInfoBean.getSSiteURL()); j,CVkA*DY  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K~Z$NS^W&  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;b;Bl:%?  
*@zya9y9q  
X-}]?OOs  
int responseCode=httpConnection.getResponseCode(); ],xvhfZ"dn  
if(responseCode>=400) 53O}`xX!6  
{ .kZ<Q]Vk  
processErrorCode(responseCode); -PLh|  
return -2; //-2 represent access is error I6RF;m:Jw  
} tde&w=ec  
Yrmd hSY  
PIZK*Lop  
String sHeader; eg(1kDMpn  
<jIuVX  
2 3*OuY  
for(int i=1;;i++) NkY7Hg0  
{ 3R6=C~  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I|R;)[;X  
//Utility.log(in.readLine()); (Qj;B)  
sHeader=httpConnection.getHeaderFieldKey(i); 4d;.p1ro  
if(sHeader!=null) }^]TUe@a  
{ pfF2!`7pI  
if(sHeader.equals("Content-Length")) t2RL|$>F1  
{ hd~0qK  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~Zo;LSI  
break; @JU Xp  
} %WAaoR&u  
} H rI(uZ]  
else lCiRvh1K  
break; 5"2pU{xmK  
} '-M9v3itC  
} ]y~"M  
catch(IOException e){e.printStackTrace ();} H.#zbKj  
catch(Exception e){e.printStackTrace ();} !A'3Mw\Nm  
U_<k*o@:  
Wz)@k2  
Utility.log(nFileLength); {I]>!V0j!  
2"8qtG`Et  
` 3h,Cy^  
return nFileLength; Z@6xu;O  
} E<r<ObeRv`  
;>r E+k%_  
p}(pIoyUF  
//保存下载信息(文件指针位置) BT* {&'\/  
private void write_nPos() VJOB+CKE  
{ Y20T$5{#  
try{ }-T :   
output = new DataOutputStream(new FileOutputStream(tmpFile)); CC|=$(PgT  
output.writeInt(nStartPos.length); (\M+E tU<9  
for(int i=0;i<nStartPos.length;i++) HL~DIC%  
{ eoxEnCU  
// output.writeLong(nPos); Uj twOv|pF  
output.writeLong(fileSplitterFetch.nStartPos); dr^MW?{a\  
output.writeLong(fileSplitterFetch.nEndPos); QW= X#yrDO  
} p"d_+  
output.close(); h4N&Yb fo  
} ~en'E  
catch(IOException e){e.printStackTrace ();} |^C35 6M>  
catch(Exception e){e.printStackTrace ();} jYE ?wc+FT  
} -I.BQ  
@H61^K<  
\JBPZ~N3  
//读取保存的下载信息(文件指针位置) "P8( R  
private void read_nPos() OTD<3Q q  
{ #y*p7~|@  
try{ $mcq/W   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (gjCm0#_%  
int nCount = input.readInt(); h1Logm+m  
nStartPos = new long[nCount]; uy8mhB+]  
nEndPos = new long[nCount]; !m6=Us  
for(int i=0;i<nStartPos.length;i++) FC#t}4as  
{ ?9Sc KN  
nStartPos = input.readLong(); F`M`c%  
nEndPos = input.readLong(); qv)%)n  
} g [c ^7  
input.close(); |C}=  1  
} 8RjFp2) W  
catch(IOException e){e.printStackTrace ();} wPl9%  
catch(Exception e){e.printStackTrace ();} Tno 0Q +  
} *nlDN4Y[  
_6]c f!H  
PYr'1D'  
private void processErrorCode(int nErrorCode) "HtaJVp//  
{ .wf$]oQQ  
System.err.println("Error Code : " + nErrorCode); =&#t ("  
} C(&3L[  
tb;u%{S  
51Q~/  
//停止文件下载 vBYk"a6SD  
public void siteStop() g]jCR*]  
{ g<^-[w4/  
bStop = true; G!E1N(%o  
for(int i=0;i<nStartPos.length;i++) FZx.Yuv  
fileSplitterFetch.splitterStop(); q" @%WK  
T0"q,lrdxV  
,"?xy-6  
}  |Fe*t  
} Huf;A1.  
//负责部分文件的抓取 F5%IsAH  
**FileSplitterFetch.java AYv7- !Yk  
*/ n7pjj  
package NetFox; C~R,,  
cHX~-:KOr  
HleMzykF  
import java.io.*; ca,U>'(y  
import java.net.*; S3gd'Bahq  
1;JH0~403  
jS4 fANG  
public class FileSplitterFetch extends Thread { WP >VQZ&  
L16">,5  
vQmqYyOc2  
String sURL; //File URL }xpo@(e  
long nStartPos; //File Snippet Start Position Ti$_V_  
long nEndPos; //File Snippet End Position |vgYi  
int nThreadID; //Thread's ID Zb$P`~(%  
boolean bDownOver = false; //Downing is over U(5Yg  
boolean bStop = false; //Stop identical 4q*mEV  
FileAccessI fileAccessI = null; //File Access interface I\@`AU  
{QVs[ J1  
S3ZI C\2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =`.OKUAn  
{ wW|[Im&  
this.sURL = sURL; Xd5uF/w  
this.nStartPos = nStart; M`H@ % M  
this.nEndPos = nEnd; hE;BT>_dn  
nThreadID = id; zR5KC!xc  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3 uJ?;  
} 91M5F$  
0N):8`dY  
s3y"y_u  
public void run() tf6 Zz[  
{ =6gi4!hE  
while(nStartPos < nEndPos && !bStop) B~2M/&rM\  
{ 'Xu3]'m*  
j.+ }Z |  
S^A+Km3VB  
try{ DeTLh($\  
URL url = new URL(sURL); G<Y}QhFU  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yny1i9 y  
httpConnection.setRequestProperty("User-Agent","NetFox"); {9- n3j}  
String sProperty = "bytes="+nStartPos+"-"; *{dMo,.eI  
httpConnection.setRequestProperty("RANGE",sProperty); C=`MzZbJ  
Utility.log(sProperty); t(p}0}Pp  
V z-]H]MW,  
`NCH^)  
InputStream input = httpConnection.getInputStream(); -ju}I  
//logResponseHead(httpConnection); i=jY l  
@.} @K  
R<;;Ph  
byte[] b = new byte[1024]; t^"8 v3'h  
int nRead; J*t_r-z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mZ~f?{  
{ Z+2 j(  
nStartPos += fileAccessI.write(b,0,nRead); 1!Afq}|  
//if(nThreadID == 1) "mc ]^ O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Or :P*l  
}  }A&I@2d  
%PC8}++  
@bZ,)R  
Utility.log("Thread " + nThreadID + " is over!"); @k)[p+)E  
bDownOver = true; YR u#JYti  
//nPos = fileAccessI.write (b,0,nRead); ,&G !9}EC  
} Lm*PHG  
catch(Exception e){e.printStackTrace ();} 0A')zKik  
} .1 jeD.l  
} , FR/X/8  
"x O+  
G rI<w.9X  
//打印回应的头信息 wicW9^ik  
public void logResponseHead(HttpURLConnection con) dZCnQIS  
{ v (=E R%  
for(int i=1;;i++) $8`"  
{ SE6c3  
String header=con.getHeaderFieldKey(i); 7KN+ @6!x  
if(header!=null) ^/~C\ (  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;),vUu,k  
Utility.log(header+" : "+con.getHeaderField(header)); GQDW}b8  
else A+hA'0isF@  
break; d fSj= 4  
} 1u~a*lO}  
} 5em*9Ko  
j7~Rw"(XQc  
}z5u^_-m  
public void splitterStop() ~W-5-Nl{s  
{ 5 Q/yPQN  
bStop = true; rUZ09>nDy  
} +h8`8k'}-2  
UmG|_7  
BbhC 0q"J  
} .yB{+  
R p0^Gwa  
C(kL=WD   
/* cVl i^*se  
**FileAccess.java avW33owb@  
*//文件访问(定位,写) {xf00/  
package NetFox; Q^):tO]!Ma  
import java.io.*; NRazI_Z  
(Ta(Y=!uq  
W0<2*7s  
public class FileAccessI implements Serializable{  vUR gR  
Xn02p,,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pO)5NbU  
RandomAccessFile oSavedFile; kAq#cLprG  
long nPos; 77-G*PI*I  
p$mt&,p  
KPA.5,ai  
public FileAccessI() throws IOException N v6=[_D  
{ qWD(rq+9  
this("",0); O bc>f|l]  
} u}89v1._Jn  
q4Mv2SPT  
m .R**g  
public FileAccessI(String sName,long nPos) throws IOException f$qkb$?]}  
{ }6gum  
oSavedFile = new RandomAccessFile(sName,"rw"); I.it4~]H  
this.nPos = nPos; 1rON8=E  
oSavedFile.seek(nPos); rTqGtmulG  
} z fu)X!t^  
73JrK_h  
b4 Pa5 w  
public synchronized int write(byte[] b,int nStart,int nLen) #3?}MC  
{ D# gC-,  
int n = -1; =yWdtBng  
try{ +G)a+r'0Q  
oSavedFile.write(b,nStart,nLen); ^Hz1z_[X@  
n = nLen; lN x7$z`  
} Y|buQQ|  
catch(IOException e) A=wG};%_  
{ )r?- _qj=  
e.printStackTrace (); k; >Vh'=X  
} D 4sp+   
<6+T&Ov6  
7"1]5\p^g  
return n; ~_ u3_d.  
} \2CEEs'  
Yr[& *>S  
R?M>uaxn  
} L_o/fTz4  
=MT'e,T  
'$ [%x  
/* =|dHD  
**SiteInfoBean.java V>D}z8w7  
*/ U+zntB  
package NetFox; V[n,fEPBr  
ja6V*CWb  
%M:$ML6b<  
public class SiteInfoBean { fk!9` p'  
zbgGK7  
]E6r )C  
private String sSiteURL; //Site's URL x"r,l/gzy  
private String sFilePath; //Saved File's Path =}YX I  
private String sFileName; //Saved File's Name wNU;gz  
private int nSplitter; //Count of Splited Downloading File .A0fI";Q  
$hMD6<e  
Qe-PW9C  
public SiteInfoBean() <W+9 h0c  
{//nSplitter的缺省值为5 AH_qZTv0{Q  
//default value of nSplitter is 5 "BZ@m:I6hy  
this("","","",5); 3O;"{E= <  
} }Rw6+;  
X4{<{D`0t8  
"Q{ l])N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) | AiMx2  
{ t7Mq>rFB  
sSiteURL= sURL; JKy~'>Q  
sFilePath = sPath; )?pnV":2Y  
sFileName = sName; UmY{2 nzY  
this.nSplitter = nSpiltter; q@tym5  
_07$TC1  
LR';cR;  
} #jd.i  
|(AFU3 ~  
O<E8,MCA[a  
public String getSSiteURL() %k~ezn  
{ Dt{WRe\#  
return sSiteURL; (L yKo  
} K)5j  
aNA ]hl  
,HI% ym  
public void setSSiteURL(String value) q^?a|l  
{ Qqx!'fft  
sSiteURL = value; Cy *.pzCi  
} [P6m8%Y|s  
kdp^{zW}  
#Ge_3^'  
public String getSFilePath() i,S1|R  
{ sN2m?`?"G  
return sFilePath; `- (<Q;iO  
} WIuYSt)h  
 g[bu9i  
]^T-X/v9  
public void setSFilePath(String value) `oH4"9&]k3  
{ SN]g4}K-  
sFilePath = value; Ln t 1  
} lRNm &3:-  
iQS,@6  
Js vdC]+  
public String getSFileName() `( w"{8laB  
{ _ Yc"{d3S  
return sFileName; j9l32<h7]  
} 3 ^K#\*P  
Ga-cto1Y  
cpALs1j:  
public void setSFileName(String value) ch25A<O<R.  
{ #9Ect@?N0  
sFileName = value; V1pBKr)v  
} `*BV@  
6q>}M  
&9|L Z9K  
public int getNSplitter() :`Ut.E~.  
{ ,.}%\GhY  
return nSplitter; 6`20  
} 9 M%Gnz  
nO!&;E&  
RV);^, b  
public void setNSplitter(int nCount) ar6+n^pi0]  
{ |cgjn*a?M  
nSplitter = nCount; UoKVl-  
} tfZ@4%'  
} qw?(^uZNW  
(CY D]n  
+:4>4=  
/* 3ce$eZE  
**Utility.java =QGmJ3  
*/ x^EW'-a  
package NetFox; NkO+ )=  
m#Z&05^  
; +(VO  
public class Utility { {Dk!<w I)  
d;]m wLB0  
E #B$.K  
public Utility() J-<_e??  
{ /I!62?)-*  
3Ovx)qKxd  
,[zSz8R  
} ;Q^>F6+_m  
 WZY+c  
//线程睡眠 (RV#piM  
public static void sleep(int nSecond) >}%#s`3W1_  
{ AvB=/p@]  
try{ bxtH`^  
Thread.sleep(nSecond); r)>3YM5  
} v_Sa0}K9  
catch(Exception e) ",D!8>=s  
{ DXI4DM"15I  
e.printStackTrace (); 8FMxn{k2  
} EJ#I7_  
} q,O_y<uw  
KFwuz()7  
//日志 yxHo0U  
public static void log(String sMsg) ,?erAI  
{ -grmmE]/  
System.err.println(sMsg); Qn.dL@W  
} &1yJrj9y  
0NGth(2  
z k/`Uz  
public static void log(int sMsg) 6PYt>r&TO  
{ W"\}##  
System.err.println(sMsg); 6j XDLI  
} 'z AvQm  
} =eUKpYI  
GdI,&| /  
ye9GBAj /  
/* 2[ofz}k]r)  
**TestMethod.java %UrNPk  
*/ I`X!M!dB)  
package NetFox; [`b,SX x  
]tN)HRk1  
N6"sXw m  
public class TestMethod { rzIWQFv  
@Kz,TP!%A  
">CRFee0  
public TestMethod() eyJWFJh  
{ ///xx/weblogic60b2_win.exe gv>DOez/  
try{ jVd`J  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "Gp Tmu?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w01[oU$x=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); z+7V}aPM  
fileFetch.start(); bE.<vF&  
} 4@3\Ihv  
catch(Exception e){e.printStackTrace ();} c-(RjQ~M5  
N,-C+r5}<4  
&gY578tU  
} K~,!IU_QG  
J<"K`|F  
5>.ATfAsV  
public static void main(String[] args) Ie/_gz^  
{ <<u]WsW{C  
new TestMethod(); (m:Q'4Ep  
} ) hs&?: )  
} \tYImh  
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