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http断点续传简单实现(java)

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/* z;#DX15Rj  
**SiteFileFetch.java Zs$Qo->F  
*/ i$[wkQ>$  
package NetFox; '#;%=+=;  
import java.io.*; uaX#nn?ws  
import java.net.*; lVw77bZ  
0|D^_1W`R  
['*{f(AI  
public class SiteFileFetch extends Thread { G[pDKELL  
vZ rE9C }  
p H5iv>H  
SiteInfoBean siteInfoBean = null; //文件信息Bean |\ZsoA  
long[] nStartPos; //开始位置 qId-v =L  
long[] nEndPos; //结束位置 T[z}^"  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +p:?blG  
long nFileLength; //文件长度 JFJ_ PphvD  
boolean bFirst = true; //是否第一次取文件 0c$0<2D%  
boolean bStop = false; //停止标志 n0nvp@?7bJ  
File tmpFile; //文件下载的临时信息 5*q!:$ W  
DataOutputStream output; //输出到文件的输出流 "<e<0::  
^h c&rD)_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) %y{f] m  
public SiteFileFetch(SiteInfoBean bean) throws IOException #)qn$&.H  
{ "M GX(SQ  
siteInfoBean = bean; RSK~<Y@]q{  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _D{V(c<WD  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); R.Plfm06Ue  
if(tmpFile.exists ()) j/oM^IY  
{ |<Cz#| ,q  
bFirst = false; R>r@I_  
read_nPos(); ~_!lx  
} udEJo~u  
else eplz5%<  
{ \A{ [2  
nStartPos = new long[bean.getNSplitter()]; (O$PJLI  
nEndPos = new long[bean.getNSplitter()]; M_:_(y>l  
} *FINNNARB  
.tg2HKD_lW  
3 N5un`K7  
h~!KNF*XW  
} zq:+e5YT?T  
j56#KNAha  
L,(H(GeX  
public void run() gB&8TE~Y  
{ Y<x;-8)*  
//获得文件长度 ut<0-  
//分割文件 }!&Vcf  
//实例FileSplitterFetch V!|:rwG2  
//启动FileSplitterFetch线程 w$D&LA}(M  
//等待子线程返回 y1oQ4|KSI  
try{ L.E6~Rv  
if(bFirst) 9AA_e ~y  
{ BA5b;+o-  
nFileLength = getFileSize(); ]12ypcf  
if(nFileLength == -1) >Q`\|m}x)Q  
{ K5h2 ~  
System.err.println("File Length is not known!"); *hk8[  
} D~(f7~c%  
else if(nFileLength == -2) SZ;Is,VgU4  
{ k3 YDnMRA9  
System.err.println("File is not access!"); 2!}:h5   
} VV$$t;R/  
else AjW5H*  
{ &e-MOM2&  
for(int i=0;i<nStartPos.length;i++) PsV1btq]  
{ o>#ue<Bc6  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &f;<[_QI=  
} N084k}io  
for(int i=0;i<nEndPos.length-1;i++) (>LJv |wn  
{ PQ#zF&gL9t  
nEndPos = nStartPos[i+1]; vmY 88Kx&S  
} 4P>4d +  
nEndPos[nEndPos.length-1] = nFileLength; w[/_o,R  
} &4dh$w]q  
} ?k}"g$JFn  
g5\EVcHkz  
;PA^.RB  
//启动子线程 4GL-3e  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |})7\o  
for(int i=0;i<nStartPos.length;i++) Rg3cqe#O/  
{ G2,9$8qE  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yu`KHvur  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (L2:|1P)  
nStartPos,nEndPos,i); |)4aIa  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]bui"-tlK  
fileSplitterFetch.start(); 1p|h\H  
} #C`IfP./  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8M_p'AR\,y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]E:P-xTwaI  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W pdn^=dhL  
nEndPos = " + nFileLength); *oW^P~m/  
// fileSplitterFetch[nPos.length-1].start(); fl4z'8P"(  
X`+8r O[  
F4#^jat{  
//等待子线程结束 $lC*q  
//int count = 0; in[yrqFb7t  
//是否结束while循环 M In6p  
boolean breakWhile = false; &l<~Xd#  
Z2t r?]  
KJLC2,  
while(!bStop) k/`WfSM\.  
{ ITmW/Im5  
write_nPos(); Vlka+$4!  
Utility.sleep(500); %z_L}L  
breakWhile = true; $.g)%#h:  
,Qw\w,  
?%]?#4bkc  
for(int i=0;i<nStartPos.length;i++) W3h{5\d!  
{ `;R [*7  
if(!fileSplitterFetch.bDownOver) WNa#X]*E)  
{ /BaXWrd+  
breakWhile = false; Wb7z&vj  
break; :8CYTEc  
} M6MtE_E  
} q]}1/JZS  
if(breakWhile) 1f/8XxTB  
break; 6tDCaB  
#R#o/@|  
L>PPAI  
//count++; 'y<<ce*   
//if(count>4) by{ *R  
// siteStop(); R c.8j,]  
} uTq)Ets3  
*9?T?S|^$F  
)tB1jcI;  
System.err.println("文件下载结束!"); :{tj5P!S  
} <M,A:u\qSQ  
catch(Exception e){e.printStackTrace ();} V!3.MQM  
} WER\04%D\m  
LqOjVQxz  
~p'DPg4  
//获得文件长度 Hrd z1:#6,  
public long getFileSize() -g6C;<Y  
{ 6lKM5,Oa  
int nFileLength = -1; J@4,@+X  
try{ CNRiK;nQ  
URL url = new URL(siteInfoBean.getSSiteURL()); Ts~)0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,2y " \_  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9tZ+ ?O5  
Hc"FW5R  
4[$D3,A  
int responseCode=httpConnection.getResponseCode(); qt !T%K  
if(responseCode>=400) K7 N)VG  
{ G"'[dL)N>  
processErrorCode(responseCode); ^1 P@BRh  
return -2; //-2 represent access is error 1X45~  
} B<A=U r  
(wtw1E5X  
|n_es)A  
String sHeader; ktMUTL(B  
V.8pxD5 s  
@N'0:0Nb_  
for(int i=1;;i++) sIZ|N"2]A*  
{ i H^Gv*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dAZh# i[  
//Utility.log(in.readLine()); )U':NV2  
sHeader=httpConnection.getHeaderFieldKey(i); RlH~<|XK  
if(sHeader!=null) mI[$c"!BD  
{ Oy `2ccQ#  
if(sHeader.equals("Content-Length")) yN Bb(!u  
{ UFED*al#  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M\f1]L|8d  
break; tHj |_t  
} 5%5z@Ka  
} :le"FFfk  
else PilV5Gg  
break; Q.N, Q`P  
} ^z^ UFW  
} r,` 59  
catch(IOException e){e.printStackTrace ();} s=uWBh3J  
catch(Exception e){e.printStackTrace ();} I'NE>!=Q  
8O)!{gB  
)/:&i<Q:  
Utility.log(nFileLength); M]Y72K^  
#n[1%8l,  
#{t?[JUn  
return nFileLength; :cmQ w  
} (M5{y` Kk  
g7|$JevR0  
?B&@  
//保存下载信息(文件指针位置) ly{Q>MBM  
private void write_nPos() 8-wW?YTG  
{ LQnkpy3A  
try{ '|\et aD  
output = new DataOutputStream(new FileOutputStream(tmpFile)); X2MQa:yksP  
output.writeInt(nStartPos.length); ;bZIj` D(  
for(int i=0;i<nStartPos.length;i++) f.o,VVYi  
{ n tfwR#j  
// output.writeLong(nPos); .o2]ndT/J  
output.writeLong(fileSplitterFetch.nStartPos); 8%$Vj  
output.writeLong(fileSplitterFetch.nEndPos); 4RH'GnLa  
} &tULSp@J  
output.close(); 4<['%7U_[  
} sh6F-g  
catch(IOException e){e.printStackTrace ();} fDn|o"  
catch(Exception e){e.printStackTrace ();} ^Fl6-|^~  
} e%v<nGN.-  
6!,Am^uXM  
K$H>/*&'~  
//读取保存的下载信息(文件指针位置) `J>76WN  
private void read_nPos() "rjqDpH  
{ :\*<EIk(  
try{ +G!N@O  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ERW>G {+  
int nCount = input.readInt(); PC| U]  
nStartPos = new long[nCount]; J {gqm  
nEndPos = new long[nCount]; U#O 6l-xe]  
for(int i=0;i<nStartPos.length;i++) _u`NIpXSP  
{ ?/_8zpW  
nStartPos = input.readLong(); ? [?{X~uq  
nEndPos = input.readLong(); H:X=v+W  
} .qyk[O  
input.close(); -}lcMZY  
} 959i2z  
catch(IOException e){e.printStackTrace ();} K)Nbl^6x  
catch(Exception e){e.printStackTrace ();} FQR{w  
} 8+&] q#W3  
fb5]eec  
fq){?hk~O  
private void processErrorCode(int nErrorCode) M-!eL<  
{ A2o ;YyF  
System.err.println("Error Code : " + nErrorCode); }}3*tn<6  
} Ojkbv  
rSIb1zJ  
lD!o4ZAo  
//停止文件下载 ~RVx~hh  
public void siteStop() n% w36_  
{ /3*75  
bStop = true; *f~X wy"  
for(int i=0;i<nStartPos.length;i++)  0gBD  
fileSplitterFetch.splitterStop(); %d+:0.+`n  
EO'[AU%~  
D?rQQxb  
} p6(n\egR  
} 4-`C !q  
//负责部分文件的抓取 (9h{7<wD`  
**FileSplitterFetch.java B.&ly/d  
*/ W'\{8&:!  
package NetFox; I"E5XVC);  
E[J7FgU)<S  
vrsO]ctI  
import java.io.*; ^5biD9>M  
import java.net.*; >2 gemTy  
NYD#I{h  
dL<okw  
public class FileSplitterFetch extends Thread { Cw]Q)rX{  
fmH$ 1C<  
"sz)~Q'W5  
String sURL; //File URL 5gg_c?Vh/  
long nStartPos; //File Snippet Start Position :8U=L'4  
long nEndPos; //File Snippet End Position __""!Yz  
int nThreadID; //Thread's ID *k'oP~:fT  
boolean bDownOver = false; //Downing is over ~130"WQ;  
boolean bStop = false; //Stop identical U]dz_%CRP  
FileAccessI fileAccessI = null; //File Access interface A'qJke=  
De[!^/f;T  
h2+vl@X  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OWCd$c_(  
{ mFOuE5  
this.sURL = sURL; >Vc_.dR)E  
this.nStartPos = nStart; !z X`M1J  
this.nEndPos = nEnd; o[^%0uVF  
nThreadID = id; .x$+ 7$G  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -MoI{3a  
} Ul OoMGg  
?<,9X06dP  
[ V()7  
public void run() v')Fq[H  
{ |UM':Ec  
while(nStartPos < nEndPos && !bStop) L #p-AK  
{ i NzoDmE*  
#"%oz^~\  
#b []-L!  
try{ 1=O Xi!G  
URL url = new URL(sURL); ~m y\{q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uXW<8( %W  
httpConnection.setRequestProperty("User-Agent","NetFox"); sN 1x|pkN  
String sProperty = "bytes="+nStartPos+"-"; $I~=t{;"XV  
httpConnection.setRequestProperty("RANGE",sProperty); S1wt>}w0$  
Utility.log(sProperty); 2pH2s\r<UJ  
25*/]i u  
-ZH]i}$  
InputStream input = httpConnection.getInputStream(); XCoN!~  
//logResponseHead(httpConnection); e2UbeP  
,\4@Ao  
c, \TL ]  
byte[] b = new byte[1024]; O[3J Px  
int nRead; <^|8\<J  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .l"_f  
{ 2X;,s`)  
nStartPos += fileAccessI.write(b,0,nRead); {_|~G|Z  
//if(nThreadID == 1) ' ~lC85  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I<z /Y?  
} .RH}/D  
o;M"C[  
d%VGfSrKq  
Utility.log("Thread " + nThreadID + " is over!"); {l.) *#O  
bDownOver = true; 'CjcOI s  
//nPos = fileAccessI.write (b,0,nRead); ny'~pT'00  
} "d/x`Dx  
catch(Exception e){e.printStackTrace ();} 0wB ?U~  
} l~AmHw e  
} -lRXH7|X  
cgc| G  
$T tCVR  
//打印回应的头信息 ;n00kel$  
public void logResponseHead(HttpURLConnection con) v)!Rir5  
{ ?Q="w5OOD  
for(int i=1;;i++) 5@P2Z]Q  
{ c_x6FoE;L  
String header=con.getHeaderFieldKey(i); k]l M%  
if(header!=null) v0jRoE#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [ahD%UxO5  
Utility.log(header+" : "+con.getHeaderField(header)); *I(>[m!  
else 2TmQaDu%b  
break; jl{>>TW{x  
} )i0\U  
} %L:e~*  
?lnX."eAdB  
H5S>|"`e`e  
public void splitterStop() zK(9k0+s  
{ YU9xANi6  
bStop = true; )/HSt%>  
} I{JU<A,&  
W=&\d`><k  
:-xp'_\L  
} Uxn_nh  
m!er "0  
vK!,vKa.  
/* R4 ;^R  
**FileAccess.java MM3X! tq  
*//文件访问(定位,写) $T8Ni!#/C  
package NetFox; p )etl5  
import java.io.*; ~=aGv%vX  
eA$9)K1GO  
Mou>|U 1e"  
public class FileAccessI implements Serializable{ Xnt`7L<L  
,oT?-PC$z  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q*{i/=~  
RandomAccessFile oSavedFile; QY8I_VF  
long nPos; 67+ K ?!,  
'M=(5p  
m4<8v  
public FileAccessI() throws IOException xop9*Z$  
{ ^SpD)O{  
this("",0); MlkTrKdGi  
} T?N' k=   
sycN  
R;.zS^LL  
public FileAccessI(String sName,long nPos) throws IOException S7P](F=n#  
{ QKL5! L9`  
oSavedFile = new RandomAccessFile(sName,"rw"); ;26a8g(  
this.nPos = nPos; -Mb nYs)  
oSavedFile.seek(nPos); UO5^4  
} E}-Y@( [  
36` aG Y  
&[`p qX  
public synchronized int write(byte[] b,int nStart,int nLen) eh2w7 @7Q  
{ \m1r(*Ar  
int n = -1; k|F<?:C  
try{ .t.H(Q9  
oSavedFile.write(b,nStart,nLen); /k|y\'<  
n = nLen; , ?WTX  
} - U!:.  
catch(IOException e) (Gf1#,/3~  
{ ?w`uv9NUJ8  
e.printStackTrace (); 1/c7((]7(,  
} '*MNRduE6  
U 3aY =8B  
Qv(}*iq]  
return n; }_u1'  
} ?k<i e2  
P6&@fwJ<  
u7ZSs-LuHw  
} F&<si:}KB  
{1li3K&0s  
6]^ShOX_Z  
/* A1Ia9@=Mf  
**SiteInfoBean.java L,*2t JcC<  
*/ lZ.x@hDS  
package NetFox; kzny4v[y  
v: cO+dQ  
fdc ?`4  
public class SiteInfoBean { AWsO? |YT  
jq yqOhb4  
!(~eeE}|lM  
private String sSiteURL; //Site's URL V0q./NuO  
private String sFilePath; //Saved File's Path %W~Kx_  
private String sFileName; //Saved File's Name <e-9We."  
private int nSplitter; //Count of Splited Downloading File kA1]o  
,+-l1GpL  
tsVQXvo  
public SiteInfoBean() c"Kl@ [1\~  
{//nSplitter的缺省值为5 Ox7v*[x'  
//default value of nSplitter is 5 |s`j=<rNQI  
this("","","",5); )XV|D  
} |Wd]:ijJ  
) (unL`y  
secD ` ]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pz7{dQqjk#  
{ 2a8ZU{wjn  
sSiteURL= sURL; wi^zXcVj  
sFilePath = sPath; k FE2Vv4.  
sFileName = sName; ,~u5SR  
this.nSplitter = nSpiltter; h}r*   
,r~pf (nz  
E/2kX3}  
} ^ cpQ*Fz  
^ZV1Ev8T6  
G8dC5+h  
public String getSSiteURL() Zz}Wg@&  
{ J}U);A  
return sSiteURL; piKYO+;W'  
} dZcRLLR  
&?UIe]  
z +,l"#Vv  
public void setSSiteURL(String value) .RF ijr  
{ s\2t|d   
sSiteURL = value; {U@&hE -  
} JAJo^}}{b  
!iUFD*~r~  
|s[kY  
public String getSFilePath() tS#=I.ET  
{ :EJ8^'0Q  
return sFilePath; x}v]JEIf[Q  
} Jm8{@D%  
[&12`!;j  
~,[-pZ <  
public void setSFilePath(String value) [Q+8Ku  
{ 2..b/  
sFilePath = value; u~SvR~OE  
} )y>o;^5'  
Ilt!O^  
7Nx5n<  
public String getSFileName() 4@ EY+p  
{ E57:ap)/  
return sFileName; D>Ij  
} tg =ClZ-  
v:/+Oz Y  
<ua`WRQr  
public void setSFileName(String value) @ 3n;>oi  
{ [R V_{F:'  
sFileName = value; -Pds7}F8  
} ZqT8G  
=AEl:SY+  
'dJ#NT25  
public int getNSplitter() ^na8d's:  
{ bu[PQsT  
return nSplitter; Fu0"Asxce  
} yTt,/+I%gJ  
Y2lBQp8'|  
XS:W{tL!  
public void setNSplitter(int nCount) R(YhVW_l  
{ H}v.0R  
nSplitter = nCount; R`M>w MLH  
} DJ&ni`  
} vbFi# |EU  
5:S=gARz  
OYnxEdo7  
/* $H\[yg>4  
**Utility.java z"7I5N  
*/ _FpZc ?=  
package NetFox; )y~FeKh  
{tS^Q*F  
~H<oqk:O-  
public class Utility { j:|um&`)  
(L`7-6e(Ab  
C:r@)Mhq  
public Utility() ,<Ag&*YE4  
{ `.oWmBey\  
_xKuEU}  
\\ZR~f!<  
} IBP3  
Go^a~Sf$  
//线程睡眠 e6G=Bq$  
public static void sleep(int nSecond) rC !!X  
{ ShP&ss  
try{ qu8!fFQjYL  
Thread.sleep(nSecond); t(~V:+W9  
} Bqcih$`BVU  
catch(Exception e) ;`")3~M3*  
{ p :v'"A}  
e.printStackTrace (); 3VI[*b  
} 9\dpJ\  
} i}tBB~]  
Xu.Wdl/{Ra  
//日志 _DDknQP  
public static void log(String sMsg) Q>ZxJ!B<k  
{ D,3Kx ^  
System.err.println(sMsg); f6of8BOg  
} biLNR"/E  
wo#,c(  
o [ Je  
public static void log(int sMsg) lRk)  
{ R^p'gQc$   
System.err.println(sMsg); Ri   
} |>Ld'\i8  
}  iH`Q4  
~M c'~:{O  
/VmtQ{KTt+  
/* u# TNW.  
**TestMethod.java Sux/='  
*/ ia9=&Hy])  
package NetFox; yv;KKQ   
jW8,}Xs  
DXa!"ZU  
public class TestMethod { M1mx{<]A  
a23XrX  
XfYbWR  
public TestMethod() sk%Xf,  
{ ///xx/weblogic60b2_win.exe hEh` cBO  
try{ [yhK4A  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o*t4zF&n  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d:vuRK4+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); QM) ob  
fileFetch.start(); Pf:;iXH?  
} n1Wo<$#  
catch(Exception e){e.printStackTrace ();} 'PqKb%B|  
A"}Ib'  
FKH_o  
} KSYHG  
_2a)b(<tF  
B'v~0Kau  
public static void main(String[] args) dFl8'D  
{ -`A+Qp)  
new TestMethod(); m S4N%Q  
} jX; $g>P  
} "(YfvO+  
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