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http断点续传简单实现(java)

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/* ~i}/  
**SiteFileFetch.java -**fT?n  
*/ #e9XU:9 @g  
package NetFox; T(~^X-k  
import java.io.*; xlW>3'uHfa  
import java.net.*; Me;Nn$'%  
lPlJL`e  
}yCgd 5+_  
public class SiteFileFetch extends Thread { uuCVI2|  
,l\D@<F  
M49Hm[0(  
SiteInfoBean siteInfoBean = null; //文件信息Bean Z \ -  
long[] nStartPos; //开始位置 <)@^TRS  
long[] nEndPos; //结束位置 `R$bx 64  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 $>%zNq-F  
long nFileLength; //文件长度 3v<9 Z9O  
boolean bFirst = true; //是否第一次取文件 ayA_[{j%X  
boolean bStop = false; //停止标志 U(:t$SBKy  
File tmpFile; //文件下载的临时信息 #mO.[IuD  
DataOutputStream output; //输出到文件的输出流 } x'o`GuUf  
 +!wkTrV  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  uQW d1>  
public SiteFileFetch(SiteInfoBean bean) throws IOException `"bp -/  
{ [{_K[5i  
siteInfoBean = bean; .:, 9Tf  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); I]ol[ X0S  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;Y(~'KF  
if(tmpFile.exists ()) 8@I.\u)0  
{ + V-&?E(  
bFirst = false;  HYg7B  
read_nPos(); i{>YQ  
} wtGb 3D"am  
else lHPhZ(Z  
{ *P[N.5{  
nStartPos = new long[bean.getNSplitter()]; i"hn%u$V  
nEndPos = new long[bean.getNSplitter()]; P`M1sON~  
} Y+~>9-S  
2f-Or/v  
cuQ=bRIb  
6[>Zy)P  
} ]PXpzruy  
(8j@+J   
8L(KdDY  
public void run() S'v UxOAo  
{ H Sk}09GV  
//获得文件长度 .ZH5^Sv$vp  
//分割文件 :.\h.H;  
//实例FileSplitterFetch XpOQBXbt  
//启动FileSplitterFetch线程 HM\gOz  
//等待子线程返回 %w6lNl  
try{ e9?y0vT//  
if(bFirst) rHgrC MW  
{ T}A{Xu*:+H  
nFileLength = getFileSize(); o/\z4Ri)$  
if(nFileLength == -1) h$fC/Juit  
{ |n&EbOmgf  
System.err.println("File Length is not known!"); ^kj%Ekt7  
} 6~q"#94  
else if(nFileLength == -2) H\e<fi%Q  
{ QgX[?2  
System.err.println("File is not access!"); N&lKo}hk  
} \[x4  
else 9L9mi<,  
{ <i1P~  
for(int i=0;i<nStartPos.length;i++) hn u/  
{ S8Yh>j8-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); r.zJ/Tk  
} OAz -w  
for(int i=0;i<nEndPos.length-1;i++) h%@#jvh?4  
{ T?FR@. Rm  
nEndPos = nStartPos[i+1]; n?A;'\cK  
}  6@ )bZ|  
nEndPos[nEndPos.length-1] = nFileLength; R0mWVgoz  
} sFxciCpN  
} "'"dcA   
#/`V.jXt>  
P(Hh%9'(  
//启动子线程 ZCVN+::Y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :YZMR JL  
for(int i=0;i<nStartPos.length;i++) l,3[hx  
{ 5bKn6O)K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ss7XjWP.}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *,DBRJ_*7  
nStartPos,nEndPos,i); !b+Kasss9  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D<cHa |  
fileSplitterFetch.start(); V]9 ?9-r  
} 3bPvL/\Lb  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'H,l\i@"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K<+h/Ok  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nS1 D&;#Y  
nEndPos = " + nFileLength); {%b-~& F9  
// fileSplitterFetch[nPos.length-1].start(); NASRr  
)Hy|K1  
pc%_:>  
//等待子线程结束 ?5 d3k%  
//int count = 0; 5ERycC y  
//是否结束while循环 C zvi':  
boolean breakWhile = false; WChJ <[]W  
D*j\gI  
`p%&c%*A  
while(!bStop) $Mp#tH28  
{ 4m6E~_:F  
write_nPos(); F 'U G p  
Utility.sleep(500); g< {jgF  
breakWhile = true; bXiT}5mJU  
j7 D\O  
zW^@\kB0D  
for(int i=0;i<nStartPos.length;i++) NUH#  
{ /P0%4aWu=  
if(!fileSplitterFetch.bDownOver) H;$OCDRC  
{ aNCIh@m~  
breakWhile = false; Ol24A^  
break; ,#r>#fi0  
} ""ICdZ_A  
} PZ"=t!  
if(breakWhile) _`zj^*%  
break; 6F3#Rxh  
7=8e|$K_  
ZWSYh>"  
//count++; I%whM~M1+  
//if(count>4) 3say&|kJ  
// siteStop(); LdAfY0  
} "tbKKh66  
BUcze\+  
e;<=aa)}?  
System.err.println("文件下载结束!"); !285=cxz  
} wvA@\-.+  
catch(Exception e){e.printStackTrace ();} kGMI ?  
} 7PZ0  
rr# &0`]  
pVt8z|p_;{  
//获得文件长度 &la;Vu"dp  
public long getFileSize() fG5U' Vw  
{ m$:o+IH/  
int nFileLength = -1; b{t'Doe  
try{ Uok?FEN  
URL url = new URL(siteInfoBean.getSSiteURL()); l M5Xw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =?3D:k7z  
httpConnection.setRequestProperty("User-Agent","NetFox"); t3b%f`D  
N$H0o+9-Y  
,xrXby|R"  
int responseCode=httpConnection.getResponseCode(); P-VK=Y1q  
if(responseCode>=400) 969*mcq'  
{ _*+ 7*vAL  
processErrorCode(responseCode); PK5xnT:  
return -2; //-2 represent access is error w7 ]@QTC  
} Z!m0nx  
[= -?n6  
~fE@]~f>  
String sHeader; _d&FB~=  
wg*2mo  
},'2j  
for(int i=1;;i++) hof:+aW  
{ ajW[}/)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _.OajE\T  
//Utility.log(in.readLine()); ^'~+w3M@  
sHeader=httpConnection.getHeaderFieldKey(i); [|\~-6"7N|  
if(sHeader!=null) RJ1 Q.o  
{ !~cTe!T  
if(sHeader.equals("Content-Length")) C9U~lcIS  
{ *S_eYKSl  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dg4 ?,{c9W  
break; rm NqS+t  
} p UWj,&t  
} Zycu3%JI  
else z)r)w?A  
break; bH&Cbme90-  
} w3c[t~R8  
} DJ;G0*  
catch(IOException e){e.printStackTrace ();} INsc!xOQ  
catch(Exception e){e.printStackTrace ();} e;56}w  
h84}lxT^]  
^Pf FW  
Utility.log(nFileLength); [Zk|s9  
_gjsAbM  
e7ixi^Q  
return nFileLength; G@anY=D\EB  
} CEE`nn  
;Id%{1  
6)kF!/J  
//保存下载信息(文件指针位置) 1_THBL26d  
private void write_nPos() %< JjftNQ  
{ P7(+{d{  
try{ JGp~A#H&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); &+=A;Y)  
output.writeInt(nStartPos.length); EUU9JnQhBJ  
for(int i=0;i<nStartPos.length;i++) C+$dm)M/q  
{ PBb@J'b  
// output.writeLong(nPos); >n)N=Zyu  
output.writeLong(fileSplitterFetch.nStartPos); V4}9f5FR  
output.writeLong(fileSplitterFetch.nEndPos); RX%*:lXi_  
} !MNUp(:  
output.close(); w%)=`'s_  
} nM1U=Du  
catch(IOException e){e.printStackTrace ();} BDyOX6  
catch(Exception e){e.printStackTrace ();} E% Ce/n  
} nk]jIR y^T  
Z +@"  
r>sk@[4h  
//读取保存的下载信息(文件指针位置) ]QM6d(zDA  
private void read_nPos() )Fk%, H-1  
{ =9GL;z:R+  
try{ 0Np }O=>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .G#S*L  
int nCount = input.readInt(); iV[g.sP-  
nStartPos = new long[nCount]; s (J,TS#I]  
nEndPos = new long[nCount]; B0NKav  
for(int i=0;i<nStartPos.length;i++) ^wCjMi(sj  
{ PmO utYV  
nStartPos = input.readLong(); MRi QaUg2  
nEndPos = input.readLong(); mF [w-<:.d  
} ScYw3i  
input.close(); f@+[-yF  
} as- Z)h[B  
catch(IOException e){e.printStackTrace ();} &!vJ3:  
catch(Exception e){e.printStackTrace ();} :bFmw dX  
} abUvU26t  
)V%xbDdS  
(Sr&Y1D  
private void processErrorCode(int nErrorCode) pj G6v(zK  
{ z _~f/  
System.err.println("Error Code : " + nErrorCode); UMuqdLaT9  
} 8P0XY S@  
7OYNH0EH  
:O)\v!Z  
//停止文件下载 C 2Fklp6  
public void siteStop() Z!60n{T79c  
{ V|ax(tHv  
bStop = true; 2cr~/,YY  
for(int i=0;i<nStartPos.length;i++) ^[Cpu_]D  
fileSplitterFetch.splitterStop(); R_:47.qq  
a33}CVG-e3  
',?v7&  
} kXA o+l  
} tzJdUZJ  
//负责部分文件的抓取 \,i9m9;y  
**FileSplitterFetch.java aG}ju;  
*/ : I28Zi*  
package NetFox; m+||t  
>xws  
gEbe6!; q3  
import java.io.*; a H'iW)  
import java.net.*; QpwOrxI}  
t/LQ|/xo  
,J"6(nk  
public class FileSplitterFetch extends Thread { N_lQz(nG/2  
j1%o+#df  
d76k1-m\o  
String sURL; //File URL l9"0Wu@_x  
long nStartPos; //File Snippet Start Position 3~}G~ t  
long nEndPos; //File Snippet End Position pw" !iG}  
int nThreadID; //Thread's ID hC?:XVt  
boolean bDownOver = false; //Downing is over $As;Tvw.  
boolean bStop = false; //Stop identical @ |v4B[/  
FileAccessI fileAccessI = null; //File Access interface <61T)7  
AHc:6v^  
eTem RNz  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n~l9`4wJY  
{ q%%8oaEI  
this.sURL = sURL; NypM+y  
this.nStartPos = nStart; @&t ';"AE  
this.nEndPos = nEnd; hJ\IE?+  
nThreadID = id; ]/hF!eO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VliX'.-  
} 0B#9CxU%  
R)MWO5  
%^ f! = *  
public void run() xDv$z.=Y  
{ i"Hec9Ri  
while(nStartPos < nEndPos && !bStop) Md(AqaA  
{ c""*Ng*T  
N7:=%Fy(  
t+7h(?8L  
try{ @^]wT_r  
URL url = new URL(sURL); 9J h"1i>x2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jh0``{  
httpConnection.setRequestProperty("User-Agent","NetFox"); l{ja2brX  
String sProperty = "bytes="+nStartPos+"-"; JpqZVu"7  
httpConnection.setRequestProperty("RANGE",sProperty); 8\HL8^6c5  
Utility.log(sProperty); <0T5W#H`D  
4$.$j=Ct."  
GTL gj'B  
InputStream input = httpConnection.getInputStream(); "<ua G?:  
//logResponseHead(httpConnection); iq2)oC_  
'8\7(0$c  
V/5.37FSb  
byte[] b = new byte[1024]; 6t/nM  
int nRead; P1KXvc}JGe  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X-2rC  
{ a,g3 /  
nStartPos += fileAccessI.write(b,0,nRead); s\i:;`l:=5  
//if(nThreadID == 1) |& OW_*l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r8>(ayJ,  
} Xmr|k:z  
uvR9BL2=  
A2>rS   
Utility.log("Thread " + nThreadID + " is over!"); XCr\Y`,Z@  
bDownOver = true; "~-H]9  
//nPos = fileAccessI.write (b,0,nRead); z-};.!L^  
} 6Y?%G>$6  
catch(Exception e){e.printStackTrace ();} ]Hr:|2 |.  
} gq9IJ  
} vM )2F  
p|fSPSz  
X,-QxV=lc)  
//打印回应的头信息 YuufgPE*H  
public void logResponseHead(HttpURLConnection con) i4;`dCT|A  
{ rP$vZ^/c  
for(int i=1;;i++) o zg%-  
{ ZslH2#   
String header=con.getHeaderFieldKey(i); k\->uSU9  
if(header!=null) {6H%4n  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GP=i6I6C  
Utility.log(header+" : "+con.getHeaderField(header)); |m{Q_zAB  
else !R p  
break; W=b<"z]RE  
} %B9iby8)1  
} #m>Rt~(,S  
:lf;C T6$  
OSP#FjH  
public void splitterStop() bz5",8Mn  
{ /tIR}qK  
bStop = true; nADt8  
} ~q0g7?}&  
'2)c;/-E  
DXX(qk)6  
} xW|^2k  
7C~qAI6Eg  
fDe4 [QQ8  
/* 55lL aus  
**FileAccess.java p }p1>-j  
*//文件访问(定位,写) Qa*?iD  
package NetFox; _D{zB1d\0  
import java.io.*; 'zYKG5A  
?}f+PP,  
]LGp3)T-  
public class FileAccessI implements Serializable{ lIR0jgP@z  
Hgu:*iYA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H<tk/\C  
RandomAccessFile oSavedFile; <eWGvIEP[  
long nPos; g7*"*%v 2  
F\pw0^K;N  
>R|*FYam  
public FileAccessI() throws IOException /JP]5M)   
{ f1eY2UtWQ  
this("",0); gkxEy5c[  
} r]!<iw  
7\.Ax  
PT2b^PP  
public FileAccessI(String sName,long nPos) throws IOException "= H.$ +  
{ >&uG1q0p.  
oSavedFile = new RandomAccessFile(sName,"rw"); RX]x3-  
this.nPos = nPos; G`!ff  
oSavedFile.seek(nPos); _W@SCV)yH  
} 7lP3\7wD@9  
<9za!.(zu  
OBF3)L]  
public synchronized int write(byte[] b,int nStart,int nLen) }h+_kRQ  
{ `b(y 5Z  
int n = -1; b0\'JZ  
try{ w1zI"G~4/Q  
oSavedFile.write(b,nStart,nLen); s3G\L<~mB  
n = nLen; qF9rY)ifm  
} c[=%v]j:u  
catch(IOException e) m7:E7 3:  
{ to0tH^pD  
e.printStackTrace (); vBUl6EmWu  
} 4SG22$7W  
;bt@wgY  
~;ink   
return n; nMU#g])y)  
}  ]Ll <  
S}"?#=Q.%O  
Q:LyD!at  
} ^q"wd?((h  
&77]h%B >  
{Y5h*BD>  
/*  FNZB M  
**SiteInfoBean.java =N,KVMxw  
*/ `92 D]^g  
package NetFox; `R@24 )  
V:42\b7x  
b("JgE`  
public class SiteInfoBean { PN:8H>  
nf< <]iHf  
#( nheL  
private String sSiteURL; //Site's URL da@y*TO#i  
private String sFilePath; //Saved File's Path ;{|a~e?Y  
private String sFileName; //Saved File's Name Vvx(7p-GQ  
private int nSplitter; //Count of Splited Downloading File 7YbI|~  
\h^bOxh  
,8uu,,c  
public SiteInfoBean() S&-sl   
{//nSplitter的缺省值为5 C!w@Naj  
//default value of nSplitter is 5 81a&99k#  
this("","","",5); /2u;w !oi.  
} #f|-l$a)3a  
Rn{q/h  
ZP)=2'RY  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e:[ Kp6J  
{ ZNB*Azi  
sSiteURL= sURL; 9BANCW"  
sFilePath = sPath; #py7emu  
sFileName = sName; p!'wOThO`  
this.nSplitter = nSpiltter; G%YD2<V  
f.jAJ; N>  
af{;4Cr  
} va8:QHdU  
 1 ,PFz  
 v )7d  
public String getSSiteURL() 3|:uIoR{  
{ v,>F0ofJ  
return sSiteURL; %o4d4 3uZ  
} 2|}p&~G(  
mKpUEJ<a  
SATZ!  
public void setSSiteURL(String value) |[34<tIN  
{ rvE!Q=y~  
sSiteURL = value; x6DH0*[.  
} {OAy@6 +  
f| N(~  
mA^>Y_:  
public String getSFilePath() iI&SI#; _  
{ =As'vt 0  
return sFilePath; *C\4%l   
} 7 oZ-D~3  
}Pb!u9_  
cjN4U [  
public void setSFilePath(String value) D'nV &m  
{ &I(|aZx?J  
sFilePath = value; )%j)*Ymz;  
} 6l_8Q w*5I  
l3g6y 9;  
30H:x@='9  
public String getSFileName() dN*<dz+4r  
{ +}+hTY$a  
return sFileName; WZ&#O#(eO`  
} r LfS9H  
}Xc|Z.6  
"\_}"0 H  
public void setSFileName(String value) M.OWw#?p:_  
{ 5 h{Hf]A  
sFileName = value; LnJ7i"Q  
} It_yh #s  
t*}<v@,  
8=nm`7(]  
public int getNSplitter() }p- %~ Y  
{ JAiV7v4&R  
return nSplitter; :m$%D]WY  
} ^d=Z/d[  
{Zseu$c  
_^'k_ a  
public void setNSplitter(int nCount) ;%k%AXw  
{ t#pY2!/T3  
nSplitter = nCount; Gc 8  
}  zIAMM  
} 15eHddd  
l%w7N9  
z:fhq:R(  
/* @pS[_!EqYz  
**Utility.java d?{2A84S  
*/ '\_)\`a|  
package NetFox; fglZjT  
',&MYm\  
[&`>&u@MK  
public class Utility { AMm O+E?  
^X;>?_Bk  
eD(a +El}  
public Utility() /6.b>|zF  
{ #xo&#FIH  
(@#Lk"B  
+es6c')  
} %4-pw|':  
`fV$'u  
//线程睡眠 P<(mH=K  
public static void sleep(int nSecond) iLI]aZ   
{ {r}}X@|5  
try{ >WEg8'#O  
Thread.sleep(nSecond); iGlZFA  
} :OZhEBL&b  
catch(Exception e) UCWU|r<s,  
{ enr mjA&3  
e.printStackTrace (); A3$b_i@P  
} sI'HS+~pU  
} _ o(h]G1].  
W P&zF$  
//日志 24Tw1'mW  
public static void log(String sMsg) UmuFzw^  
{ +~v(*s C  
System.err.println(sMsg); gc:>HX );)  
} M*H G4(n0  
&ivIv[LV  
igL^k`&5^"  
public static void log(int sMsg) R{B~Now3  
{ `qgJE_GC  
System.err.println(sMsg); l{AT)1;^  
} <>oW f  
} `ouzeu9}  
:F\f}G3  
~e8n yB  
/* Ye6O!,R  
**TestMethod.java u5ygbCm  
*/ (Vv]:Y]  
package NetFox; 19t*THgq  
yB1>83!q  
u\wd<<I']  
public class TestMethod { p'4P2   
:<gk~3\  
FM)*>ax{  
public TestMethod() ~] 2R+  
{ ///xx/weblogic60b2_win.exe hzb|:  
try{ 1aG}-:$t'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J;`~ !g  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NZ5~\k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); A'8K^,<  
fileFetch.start(); Y c kbc6F  
} pH [lj8S  
catch(Exception e){e.printStackTrace ();} ;gnr\C*G  
:bDA<B6bb  
;I'/.gW;{  
} M(uB ;Te  
I>#ChV)(#  
u'1=W5$rK  
public static void main(String[] args) T7~v40jn|  
{ 9A(K_d-!H  
new TestMethod(); dCTpO  
} Q%2Lyt"(  
} CF"3<*%x  
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