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http断点续传简单实现(java)

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/* DYRE1!  
**SiteFileFetch.java dy:d=Z  
*/ _Adsq8sFW  
package NetFox; %v4ZGtKC@  
import java.io.*; Tpzw=bC^  
import java.net.*; Rd%0\ B  
KlU qoJ;"  
d#\W hRE  
public class SiteFileFetch extends Thread { "2;N2=~7  
x=,8[W#XT  
0H[LS  
SiteInfoBean siteInfoBean = null; //文件信息Bean T~J? AKx  
long[] nStartPos; //开始位置 ]l[2hy= cV  
long[] nEndPos; //结束位置 l>7r2;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 J]fS({(\I  
long nFileLength; //文件长度 |zpx)8Q  
boolean bFirst = true; //是否第一次取文件 :;4SQN{2 O  
boolean bStop = false; //停止标志 yvxl_*Ds8  
File tmpFile; //文件下载的临时信息 ^>m^\MuZ  
DataOutputStream output; //输出到文件的输出流 V;93).-$  
Dp^/gL=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {?i)K X^  
public SiteFileFetch(SiteInfoBean bean) throws IOException D{C:d\ e)$  
{ J^ ={}  
siteInfoBean = bean; cy1jZ1)  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); doD>m?rig3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ><Uk*mwL  
if(tmpFile.exists ()) T"!EK&  
{ l!IGc:  
bFirst = false; ``9 GY  
read_nPos(); ^,V[nfQR  
} xvDI 4x&  
else uvB1VV4  
{ ` X}85  
nStartPos = new long[bean.getNSplitter()]; / Z!i;@Wf  
nEndPos = new long[bean.getNSplitter()]; D$nK`r  
} &p"(-  
3hS6j S  
l h/&__  
M<[ ?g5=#  
} irMd jG  
%MJ;Q?KB  
8#59iQl  
public void run() mP-2s;q  
{ Y {c5  
//获得文件长度 !Iq{ 5:  
//分割文件 &1GUi{I  
//实例FileSplitterFetch bGv4.:)  
//启动FileSplitterFetch线程 p4> ,Fwy2  
//等待子线程返回 CLN+I'uX0  
try{ %S#WPD'Y  
if(bFirst) `|<+  ?  
{ (~()RkT  
nFileLength = getFileSize(); NHiq^ojk  
if(nFileLength == -1) m mw-a0  
{ 6c<ezEJ  
System.err.println("File Length is not known!"); Q6^x8  
} 6fwY$K\X  
else if(nFileLength == -2) ~HDdO3  
{ k/lFRi-i  
System.err.println("File is not access!"); +v15[^F  
} 2c:f<>r0y  
else ',mW`ZN  
{ /cY^]VLe  
for(int i=0;i<nStartPos.length;i++) eb!_ie"D  
{ nb+m.X  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]rW8y%yD  
} i2`0|8mw'  
for(int i=0;i<nEndPos.length-1;i++) ;nB2o-%  
{ T:!MBWYe|  
nEndPos = nStartPos[i+1]; LfX0Z=<  
} ]k+m=OR{/  
nEndPos[nEndPos.length-1] = nFileLength; r4eUZ .8R  
} 9*}gl3y  
} X+ f9q0  
rsF:4G"%  
SRz&Nb  
//启动子线程 TzM=LvA  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2Q ayM?k8  
for(int i=0;i<nStartPos.length;i++) (0jr;jv  
{ #":a6%0Q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7 g6RiH}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 59!)j>f  
nStartPos,nEndPos,i); fLB1)kTS  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 77We;a  
fileSplitterFetch.start(); .3wY\W8Dr-  
} o3h-=t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kx{!b3"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D1X{:#|  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]\;xN~l  
nEndPos = " + nFileLength); 'G#SLqZy  
// fileSplitterFetch[nPos.length-1].start(); A=`* r*  
<qY5SV,  
F?4Sz#  
//等待子线程结束 ;^-:b(E  
//int count = 0; xP@/9SM  
//是否结束while循环 r nBOj#N  
boolean breakWhile = false; >XE`h 9  
,w`~K:b.  
yJD >ny  
while(!bStop) aRwnRii  
{ f7+Cz>R  
write_nPos(); (9GbG"   
Utility.sleep(500); ./w{L"E  
breakWhile = true; R6@uM<  
9<cOYY  
jXR16|  
for(int i=0;i<nStartPos.length;i++) 5(J^N  
{ /V^sJ($V$~  
if(!fileSplitterFetch.bDownOver) "ahvNx;x  
{ Qpu3(`d<  
breakWhile = false; ;CmOsA,1  
break; !N~*EI$  
} \ 4gXY$`@  
} -g~~]K%  
if(breakWhile) dDlG!F_=  
break; <lo`q<q  
GqUSVQ  
)%mAZk-*;^  
//count++; sh6(z?KP  
//if(count>4) =_QkH!vI  
// siteStop(); l)8sw=  
} 7/>a:02  
A&N*F"q  
Sdc*rpH"(  
System.err.println("文件下载结束!"); Yx1 D)  
} `-O= >U5nH  
catch(Exception e){e.printStackTrace ();} 2R`u[  
} #&siHHs \  
zilaP)5x6  
&O tAAE  
//获得文件长度 og-]tEWA1  
public long getFileSize() \"d?=uFe  
{ ?}sOG?{  
int nFileLength = -1; v*r9j8  
try{ g rbTcLSF  
URL url = new URL(siteInfoBean.getSSiteURL()); B>|5xpZM12  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &;v!oe   
httpConnection.setRequestProperty("User-Agent","NetFox"); ;BI)n]L  
s*JE)  
3qo e^e  
int responseCode=httpConnection.getResponseCode(); o}~3JBn T  
if(responseCode>=400) yWHne~!  
{ sXB+s  
processErrorCode(responseCode); V2Y$yV8g1  
return -2; //-2 represent access is error >&hX&,hG  
} m2b`/JW  
w3bIb$12  
u^=@DO'  
String sHeader; YMu)  
8^X]z|2  
},PBqWe  
for(int i=1;;i++) UC|JAZL  
{ fn1pa@P  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G (\Ckf:  
//Utility.log(in.readLine()); s.y}U5Ty?P  
sHeader=httpConnection.getHeaderFieldKey(i); g1qi\axm  
if(sHeader!=null) FpzP #;  
{ `Bu9Nq  
if(sHeader.equals("Content-Length")) EcW1;wH  
{ *V|zx#RN  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wk[)+\WQ?  
break; P<L&c_u  
} k7Oy5$##  
} d_T<5Hin  
else e?<D F.Md+  
break; :t>Q:mX(N  
} }17bV, t  
} 4$Pr|gx  
catch(IOException e){e.printStackTrace ();} #!d]PH746  
catch(Exception e){e.printStackTrace ();} 0yTQ{'Cc  
QUp?i  
(C\r&N  
Utility.log(nFileLength); ifrq  
<E}N=J'uJ  
)ddsyFGW  
return nFileLength; C1 {ZW~"YI  
} xid:"y=_&  
T} 8CfG_ j  
<gcmsiB|  
//保存下载信息(文件指针位置) o)!m$Q~v  
private void write_nPos() owM mCR  
{ oD,C<[(p  
try{ \`gEu{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); iGa}3pF  
output.writeInt(nStartPos.length); CB]l[hM$  
for(int i=0;i<nStartPos.length;i++) T*\$<-^  
{ M=+M8M`Iy  
// output.writeLong(nPos); A^g>fv  
output.writeLong(fileSplitterFetch.nStartPos); hVZo"XUb  
output.writeLong(fileSplitterFetch.nEndPos); ^ LbGH<#J  
} ohplj`X[21  
output.close(); 6Ahr_{  
} 7TdQRB  
catch(IOException e){e.printStackTrace ();} 6 [ _ fD  
catch(Exception e){e.printStackTrace ();} Ilef+V^qr  
} GZ"/k<~0  
CWvlr nv  
TkT-$=i  
//读取保存的下载信息(文件指针位置) %~\  
private void read_nPos() qUg9$oh{LI  
{ v= 8VvT 8  
try{ Ky6+~>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6eo4#/+%  
int nCount = input.readInt(); H:Lt$  
nStartPos = new long[nCount]; 1p=&WM  
nEndPos = new long[nCount]; >Bx8IO1_\d  
for(int i=0;i<nStartPos.length;i++) h--45`cE  
{ ucM.Ro=@  
nStartPos = input.readLong(); ~o Fh>9u  
nEndPos = input.readLong(); eP?~- #  
} +"Ub/[J{G1  
input.close(); +!xu{2!  
} V4\56 0  
catch(IOException e){e.printStackTrace ();} xp=Zd\5W$  
catch(Exception e){e.printStackTrace ();} - 3]|[  
} 9m~t j_  
w&C1=v -h  
#%WCL'6B  
private void processErrorCode(int nErrorCode) ?\M)WDO  
{ mR,O0O}&  
System.err.println("Error Code : " + nErrorCode); ]|y}\7Aa  
} k- vA#  
B{99gwMe]  
.5z&CJDiIi  
//停止文件下载 7vq DZg  
public void siteStop() Dt|fDw$]D  
{ yDuq6`R*  
bStop = true; Pl?}>G  
for(int i=0;i<nStartPos.length;i++) "5(W[$f*]v  
fileSplitterFetch.splitterStop(); 952V@.Zp  
wo]ks}9  
oX*b<d{\N  
} Y2D >tpqNw  
} [%? hCc  
//负责部分文件的抓取 sL8>GtVo  
**FileSplitterFetch.java ;L$,gn5H  
*/ d.I%k1`(  
package NetFox; vlAy!:CV  
UeNF^6sWu0  
F;W'  
import java.io.*; kw#X]`c3  
import java.net.*; AbG&9=Ks  
D@*|24y  
[tz u;/  
public class FileSplitterFetch extends Thread { U\?+s2I)v  
,0,Oe=d  
i=V-@|Z  
String sURL; //File URL z g)|rm  
long nStartPos; //File Snippet Start Position Fq4lXlSB  
long nEndPos; //File Snippet End Position K?JV]^  
int nThreadID; //Thread's ID UT~4Cfb  
boolean bDownOver = false; //Downing is over `xGT_0&ck  
boolean bStop = false; //Stop identical \eT/%$  
FileAccessI fileAccessI = null; //File Access interface 3wo'jOb  
I<KCt2:X  
ovSH}h!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "G@E6{/  
{ Y=|CPE%V  
this.sURL = sURL; /wlFD,+8  
this.nStartPos = nStart; I[%M!_+  
this.nEndPos = nEnd; ILNXaJ'0a  
nThreadID = id; 5E0wn'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D>S8$]^Dm  
} '?b\F~$8  
K9^"NS3  
xjE7DCmA  
public void run() _V&x`ks  
{ k3#wLJ  
while(nStartPos < nEndPos && !bStop) ZLuPz#  
{ qNy-o\;XN  
8,H~4Ce3  
lj Y  
try{ # 'wL\3  
URL url = new URL(sURL); $q^O%(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sN=KRqe  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Vm Eyb  
String sProperty = "bytes="+nStartPos+"-"; 4NJVW+:2  
httpConnection.setRequestProperty("RANGE",sProperty); :Nkz,R?  
Utility.log(sProperty); &D^e<j}RQ  
8a?IC|~Pz  
+~:x}QwGT  
InputStream input = httpConnection.getInputStream(); n}f3Vrl  
//logResponseHead(httpConnection); j+ I*Xw  
=^#0.  
N7a[B>+`  
byte[] b = new byte[1024]; 51z/  
int nRead; |MVV +.X  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ig+k[`W  
{ 2G H)iUmc  
nStartPos += fileAccessI.write(b,0,nRead); 8z?$t-DO  
//if(nThreadID == 1) mcCB7<. e  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^^7gDgT  
} n00z8B1j(l  
@f\ X4!e*y  
:bI,rEW#_  
Utility.log("Thread " + nThreadID + " is over!"); }tu4z+T2  
bDownOver = true; $G)&J2zL  
//nPos = fileAccessI.write (b,0,nRead); )G mb? !/^  
} 3mybG%39  
catch(Exception e){e.printStackTrace ();} am3V9 "\  
} w{~" ;[@  
} 1R*1BStc  
QP'qG@j[:  
N=.}h\{0  
//打印回应的头信息 >}mNi:6xq  
public void logResponseHead(HttpURLConnection con) dWMccn;-m  
{ 3F;EE:  
for(int i=1;;i++) [1e.i  
{ $x/J+9Ww  
String header=con.getHeaderFieldKey(i); 3Sk5I%  
if(header!=null) EkDws `@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9GtLMpy  
Utility.log(header+" : "+con.getHeaderField(header)); makaI0M  
else U-ERhm>uk  
break; pz.Y=V\t  
} 6V+V zDo  
} =P 1RdyP  
?U=mcdqd  
}F~f&<GX6  
public void splitterStop() i[mC3ghM6,  
{ !'+\]eA  
bStop = true; :{x!g6bK@  
} kBQ5]Q"  
C+DG+_%V*S  
dvC0 <*V  
} ex{)mE4Cd  
Fka1]|j9  
5aa}FdUq  
/* K3j_C` Se  
**FileAccess.java "4KkKi  
*//文件访问(定位,写) X >3iYDe  
package NetFox; ?0? x+  
import java.io.*; 7ZL,p:f  
!Jk(&.  
 <WO&$&  
public class FileAccessI implements Serializable{ ?a*fy}A|  
zw}@nqp   
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cb\jrbj6  
RandomAccessFile oSavedFile; F">Nrj-bs  
long nPos; 0~Um^q*'3  
+oE7~64LL  
5w]DncdQ~  
public FileAccessI() throws IOException &19l k   
{ LZgwIMd  
this("",0); SJso'6 g  
} K-N]h  
A9NOeE  
H(  
public FileAccessI(String sName,long nPos) throws IOException =1%zI%  
{ iK$Vd+Lgc  
oSavedFile = new RandomAccessFile(sName,"rw"); f6keWqv<GW  
this.nPos = nPos;  JsZAP  
oSavedFile.seek(nPos); %@M00~-  
} AGw1Pl8]K  
 EGp~Vo-  
WZfk}To1#  
public synchronized int write(byte[] b,int nStart,int nLen) }|w=7^1z  
{ 0sq=5 BnO  
int n = -1; )pkhir06t  
try{ oG|?F4l*  
oSavedFile.write(b,nStart,nLen); ykErt%k<n  
n = nLen; E geG,/-`  
} 23(B43zy  
catch(IOException e) ,-w-su=J_  
{ $)kk8Q4+K  
e.printStackTrace (); jx^|2  
} *+_fP|cv  
;t.SiA  
L7~+x^kw  
return n; !=8L.^5c  
} V+4k!  
 }qgqb  
X ,V= od>  
} S!`4Bl  
@d8&3@{R^  
-D.B J(  
/* gb!@OZ c  
**SiteInfoBean.java f;@ b a[  
*/ u|_I Twk  
package NetFox; SX1Fyy6 w  
T! &[  
rahHJp.Ws  
public class SiteInfoBean { .{'Uvn  
<>&e/  
J4Q)`Y\~  
private String sSiteURL; //Site's URL Thht_3_C,f  
private String sFilePath; //Saved File's Path v*C+U$_3\1  
private String sFileName; //Saved File's Name lx A<iQia  
private int nSplitter; //Count of Splited Downloading File S0Rf>Eo4  
7?n* t  
(hRgYwUa<  
public SiteInfoBean() 89:?.'  
{//nSplitter的缺省值为5 #cSw"A  
//default value of nSplitter is 5 <3],C)Zwc  
this("","","",5); =F^->e0N  
} }iiG$?|.  
ne !j%9Ar  
[9YlLL@  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E :'  
{ dy8In%  
sSiteURL= sURL; L.I}-n  
sFilePath = sPath; 34++Rr [G  
sFileName = sName; Mc#O+'](f  
this.nSplitter = nSpiltter; B $ y44  
R:pBbA7E  
qH {8n`  
} "tg\yem  
Nj3^"}V  
s)o ,Fi  
public String getSSiteURL() k#IS ,NKE  
{ R%]9y]HQ  
return sSiteURL; 7YQK@lS  
} T}b( M*E  
?@g;[310`  
PJSDY1T  
public void setSSiteURL(String value) QYf/tQg$  
{ &4[#_(pk  
sSiteURL = value; $Z(g=nS>  
} )\I? EU8  
Up!ZCZ$RC  
<x>k3bD  
public String getSFilePath() |)!k @?_  
{ dc\u$'F@S  
return sFilePath; Yt O@n@1  
} u75)>^:I   
{'=Nb 5F  
pdcwq~4~%  
public void setSFilePath(String value) \KnD"0KW   
{ %Zv(gI`A  
sFilePath = value; I 1VEm?CQ  
} ?-.Ep0/  
K,L>  
l6}b{e  
public String getSFileName() o?Tp=Ge  
{ e8P!/x-y  
return sFileName; _/z)&0DO  
} _]?Dt%MkD  
@dT: 1s  
uz#eO|z@o  
public void setSFileName(String value) ;*37ta  
{ q_T?G e  
sFileName = value;  u_[4n  
} tmY-m,U  
.1[2 CjQ  
QE{;M  
public int getNSplitter() dPyBY ]`  
{  z7.C\l  
return nSplitter; faL^=CAe  
} gQk#l\w _  
 Z,8+@  
Y+"hu2aPkY  
public void setNSplitter(int nCount) [ilv/V<  
{ d6d(? "  
nSplitter = nCount; 4-}A'fTU8  
} xJH9qc ME  
} -Y jv&5  
0@mX4.!  
8)q]^  
/* yZ(Nv $[5  
**Utility.java yK>0[6l  
*/ i6g[E 4nk  
package NetFox; 3Ld ;zW  
+{Vwz  
sKB-7  
public class Utility { :9rhv{6Wp  
ubN"(F:!-S  
SU#P.y18%  
public Utility() < jocfTBk  
{ Zm8 u:  
+'&_V011<  
$v bAcWj  
} G}?P r4Gj  
@#ho(_U8  
//线程睡眠 EBL,E:_)  
public static void sleep(int nSecond) Z564K7IV  
{ Zxxy1Fl#.[  
try{ J:-TINeB  
Thread.sleep(nSecond); J%O4IcE  
} tx1m36a"  
catch(Exception e) (.XDf3   
{ ]x(2}h^ S  
e.printStackTrace (); !K^Z5A_;  
} s*~jvL  
} :Z]+Z_9p  
LOb'<R\p  
//日志 U37?P7i's  
public static void log(String sMsg) hC 4X Y  
{ }$k`[ivBx(  
System.err.println(sMsg); eze(>0\f  
} fe9& V2Uu  
luz%FY:  
[|;Zxb:  
public static void log(int sMsg) f$S QhK5`  
{ +8vzkfr3It  
System.err.println(sMsg); 7Ae,|k  
} g$-D?~(Z  
} Z"%O&O  
+D-+}&oW  
$8T|r+<  
/* >LaL! PnZ  
**TestMethod.java 1q233QSW)  
*/ =&*QT&e  
package NetFox; qL;T&h  
QB|fFj58u  
.lF\bA|  
public class TestMethod { =wR]X*Pan  
'hi\98y  
U#]eN[  
public TestMethod() r5qx! >  
{ ///xx/weblogic60b2_win.exe IOSoc 7+"  
try{ 7D~O/#dcc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'St= izhd  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =&b$W/l)0  
SiteFileFetch fileFetch = new SiteFileFetch(bean); -S3+ h$Y8  
fileFetch.start(); 5NvyK[w]  
} ${?exnb$  
catch(Exception e){e.printStackTrace ();} Dx# @D#  
&'ETx"  
[oN> :  
} I7z]%Z  
W*DIW;8p  
ZM^;%(  
public static void main(String[] args) Q|H cg|  
{ /,@v"mE7c!  
new TestMethod(); tfKeo|DM"  
} a*8.^SdzR  
} Qu>zO!x  
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