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http断点续传简单实现(java)

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/* eH7x>[lH.  
**SiteFileFetch.java x-c5iahp'  
*/ eCR^$z=c  
package NetFox; tl /i  
import java.io.*; 3 1c*^ZE.  
import java.net.*; F?tWx+N<{  
q#AIN`H  
,+ IFV  
public class SiteFileFetch extends Thread { S'^ q  
;o'r@4^&$R  
CyLwCS{V\  
SiteInfoBean siteInfoBean = null; //文件信息Bean d+G%\qpzQ  
long[] nStartPos; //开始位置 @:RoYvk$  
long[] nEndPos; //结束位置 Dqo#+_v  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 X+sKG5nS  
long nFileLength; //文件长度 m5 sW68  
boolean bFirst = true; //是否第一次取文件  ?;v\wx  
boolean bStop = false; //停止标志 ?o.d FKUe  
File tmpFile; //文件下载的临时信息 N$e mS  
DataOutputStream output; //输出到文件的输出流 mWYrUI  
]QHp?Ii1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 5,p;b  
public SiteFileFetch(SiteInfoBean bean) throws IOException EPn!6W5^  
{ 5- GS@fY  
siteInfoBean = bean; "`cN k26JZ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); f8[O]MrO;  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;G}  
if(tmpFile.exists ()) ,x1OQ jtY  
{ @@^iN~uf  
bFirst = false; _f";zd  
read_nPos(); B<L7`xL  
} T5|kO:CbHq  
else ;8XRs?xyd  
{ z H-a%$5  
nStartPos = new long[bean.getNSplitter()]; 'WhJ}Uo\  
nEndPos = new long[bean.getNSplitter()]; $365VTh"  
} al}J^MJ  
:8eI_X  
?R)dx uj  
#S9J9k  
} {|>Wwa2e  
[m{sl(Q  
%m dtVQ@  
public void run() 'M>m$cCMZ  
{  .fl r  
//获得文件长度 #3qeRl  
//分割文件 0h@FHw2d  
//实例FileSplitterFetch *[]E 5U  
//启动FileSplitterFetch线程 X-HE9PT.  
//等待子线程返回 k B>F(^  
try{ G@H!D[wd  
if(bFirst) "9s_[e  
{ V_SH90@)+  
nFileLength = getFileSize(); z/{X{+Z  
if(nFileLength == -1) \nZB@u;S  
{ 12n:)yQy  
System.err.println("File Length is not known!"); n6% `  
} uAPVR  
else if(nFileLength == -2) [HQ)4xG  
{ *z0d~j*W;  
System.err.println("File is not access!"); Lg7A[\c ~  
} EhHxB fAQ  
else en< $.aY  
{ {Uw 0zC  
for(int i=0;i<nStartPos.length;i++) =D/zC'l  
{ O6;"cUv  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); tON>wmN  
} sFFQ]ST2p  
for(int i=0;i<nEndPos.length-1;i++) |EE1S{!24m  
{ 6^Wep- $  
nEndPos = nStartPos[i+1]; &|>~7(  
} GF ux?8A:%  
nEndPos[nEndPos.length-1] = nFileLength; |HK:\)L%  
} ZUQ _u  
} >Wr%usNxc  
d<a|dwAeh  
O{LCHtN  
//启动子线程 '}_r/l]K  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z0Z6a Zeb  
for(int i=0;i<nStartPos.length;i++) Xi&J%N'  
{ W*C~Xba<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I$7eiW @  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +& r!%j7  
nStartPos,nEndPos,i); OjUPvR2 0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WBE>0L  
fileSplitterFetch.start(); C{}_Rb'x  
} @V*dF|# /  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q\6(_U#Tl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D`LBv,n  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B3#G  
nEndPos = " + nFileLength); !K>iSF<  
// fileSplitterFetch[nPos.length-1].start(); KMRPleF  
=5+*TL`  
sasurR|;  
//等待子线程结束 6z9 '|;,4  
//int count = 0; TQ4@|S:OF  
//是否结束while循环 Urr%SIakvM  
boolean breakWhile = false; PE%$g\#?  
1)(>'pY  
-* ,CMw  
while(!bStop) $O%{l.-O  
{ @[n#-!i  
write_nPos(); rpT.n-H>%A  
Utility.sleep(500); L80(9Y^xn  
breakWhile = true; ~Bzzu % S  
bKo %Ak,  
L!fTYX#K]  
for(int i=0;i<nStartPos.length;i++) ote,`h  
{ Wgwd?@uK  
if(!fileSplitterFetch.bDownOver)  j#](Q!  
{ i5 rkP`)j  
breakWhile = false; gfQ?k  
break; W$c@C02<  
} n<ZPWlJ  
} ;m(iKwDt  
if(breakWhile) ^dQ{vL@9b9  
break; 8+F5n!  
Kw -SOFE  
ot^pxun  
//count++; @5%&wC  
//if(count>4) "7B}hZ^)W  
// siteStop(); ?5C'9 V  
} ]\78(_o.zz  
rJ!cma  
Z3`EXs  
System.err.println("文件下载结束!"); >@YefNX6  
} tEhg',2t(  
catch(Exception e){e.printStackTrace ();} ,EB}IG ]  
} z5>I9R^q;  
H71sxek3  
K;?D^n.  
//获得文件长度 P-@MLIC{  
public long getFileSize() 7zM:z,  
{ cl4E6\?z  
int nFileLength = -1; ^Bx[%  
try{ fj_23{,/"g  
URL url = new URL(siteInfoBean.getSSiteURL()); ";K w?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >fPo_@O  
httpConnection.setRequestProperty("User-Agent","NetFox"); QZ a.c  
/DYyl/  
X]0>0=^  
int responseCode=httpConnection.getResponseCode(); <L &EH@T  
if(responseCode>=400) * DL7p8  
{ OK [J h  
processErrorCode(responseCode); {K,In)4  
return -2; //-2 represent access is error 4-(kk0]`z  
} Y=Vbs x  
% Y^J''  
oUv26t~  
String sHeader; a{5SOe;;  
#z `W ,^C  
J +6zV m  
for(int i=1;;i++) @A/k"Ax{r  
{ 1vj/6L  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  F!omkN  
//Utility.log(in.readLine()); 4U}qrN~=  
sHeader=httpConnection.getHeaderFieldKey(i); "/W[gP[y%  
if(sHeader!=null) 3N7H7(IR  
{ uDF;_bli)H  
if(sHeader.equals("Content-Length")) Fhoyji4  
{ %Sr+D{B  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9njwAKF?  
break; )BP*|URc  
} tdy2ZPVtTV  
} ;XKe$fsa~?  
else a)qan  
break; 6  63o  
}  T{YZ`[  
} MY&Jdmga  
catch(IOException e){e.printStackTrace ();} Swi# ^i  
catch(Exception e){e.printStackTrace ();} ($[wCHU`!  
RZ".?  
zZ5:)YiW-  
Utility.log(nFileLength); ep0,4!#FAO  
!IxO''4  
S{@}ECla  
return nFileLength; zkQ[<  
} +X}i%F'  
"t@p9>  
*H>rvE.K?  
//保存下载信息(文件指针位置) rqdwQ  
private void write_nPos() \@LTXH.  
{ ^J!q>KJs  
try{ bx@l6bpQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); {T){!UVp!  
output.writeInt(nStartPos.length); *b~6 BM$  
for(int i=0;i<nStartPos.length;i++) p?@ %/!S  
{ @mp`C}x"0&  
// output.writeLong(nPos); je4l3Hl  
output.writeLong(fileSplitterFetch.nStartPos); bDI%}k9#  
output.writeLong(fileSplitterFetch.nEndPos);  6@S6E(^  
} :2 ;Jo^6Se  
output.close(); KyvZ? R  
} G0cG%sIl  
catch(IOException e){e.printStackTrace ();} Tkbao D  
catch(Exception e){e.printStackTrace ();} I[ \~ pi,  
} UM}u(;oo%)  
}pc9uvmIJ  
O] _4pP  
//读取保存的下载信息(文件指针位置) 7nZPh3%  
private void read_nPos() e#eVc'=cDR  
{ bF)G+IH  
try{ hsZ/Vnn`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~%TWF+  
int nCount = input.readInt(); nla6QlFYn*  
nStartPos = new long[nCount]; \bA Yic  
nEndPos = new long[nCount]; Z:; }  
for(int i=0;i<nStartPos.length;i++) 9>""xt  
{ R%E7 |NAG  
nStartPos = input.readLong(); bS.w<V Ew  
nEndPos = input.readLong(); DSGcxM+  
} )G? qX.D  
input.close(); d_RgKdR )k  
} >tD=t8  
catch(IOException e){e.printStackTrace ();} JTlk[ c  
catch(Exception e){e.printStackTrace ();} IgT`on3Y  
} &4#Zi.]  
bp1AN9~  
.8hI ad  
private void processErrorCode(int nErrorCode) 2h E(h  
{ Ia&R/I  
System.err.println("Error Code : " + nErrorCode); Uv^\[   
} 2|1fb-AR  
&hCbXs=  
'6KvB  
//停止文件下载 <N<Q9}`V  
public void siteStop() EeIDlm0o  
{ I7f ^2  
bStop = true; f)I5=Ijy(  
for(int i=0;i<nStartPos.length;i++) _GOSqu!3Y  
fileSplitterFetch.splitterStop(); J 3!~e+wn  
H'+7z-% G  
{4"V)9o-1>  
} :5d>^6eoB?  
} S{Y zHK  
//负责部分文件的抓取 u8e_Lqx?  
**FileSplitterFetch.java OWd'z1Yl  
*/ GkIE;7#2kX  
package NetFox; *bkb-n Kw  
!>UlvT-  
{Gxe%gu6K  
import java.io.*; /--p#Gh'  
import java.net.*; t6+m` Kq  
)?n'ZhsX  
\-<BUG]=  
public class FileSplitterFetch extends Thread { c:[k+_Zr  
V+d_1] l  
"fFSZ@,r  
String sURL; //File URL {(73*-~$  
long nStartPos; //File Snippet Start Position ]B8 A  
long nEndPos; //File Snippet End Position 0.aXg"  
int nThreadID; //Thread's ID ;*K4{wvG  
boolean bDownOver = false; //Downing is over rIb+c=|F  
boolean bStop = false; //Stop identical Vej$|nF  
FileAccessI fileAccessI = null; //File Access interface <LX\s*M)  
O5\r%&$xd  
gN&i &%*!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pO]gf$  
{ zF&VzNR2  
this.sURL = sURL; %36x'Dn ?  
this.nStartPos = nStart; }xZi Ct  
this.nEndPos = nEnd; :yay:3qv  
nThreadID = id; h8rW"8Th  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fu7:4+  
} !, 4ag1  
_Hb;)9y  
:1v,QEb\  
public void run() |rmelQ-  
{ 4=PjS<Lu8  
while(nStartPos < nEndPos && !bStop) CB@7XUR  
{ ^E&PZA\,;  
8$00\><r  
b*|~F  
try{ =Q#I@SVp2$  
URL url = new URL(sURL); ^:nc'C gP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Sn CwoxK  
httpConnection.setRequestProperty("User-Agent","NetFox"); : =QX^*  
String sProperty = "bytes="+nStartPos+"-"; qHtQ4_Zn;  
httpConnection.setRequestProperty("RANGE",sProperty); R!nf^*~  
Utility.log(sProperty); ?u|??z%  
 7WJ \nK  
VK}4 <u  
InputStream input = httpConnection.getInputStream(); {@Wv@H+4  
//logResponseHead(httpConnection); rTD+7 )E  
?vXgHDs^T  
gLiJ&H  
byte[] b = new byte[1024]; Dc9uq5l  
int nRead; k.@![w\ea  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cx}Yu8  
{ 3G} )$y3m  
nStartPos += fileAccessI.write(b,0,nRead); Z~'t'.=z  
//if(nThreadID == 1) ]TV_ p[L0B  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'C+cQLig@  
} z2=bbm:  
V>6klA}o  
F^ q{[Z  
Utility.log("Thread " + nThreadID + " is over!"); 4vhf!!1  
bDownOver = true;  MlO OB  
//nPos = fileAccessI.write (b,0,nRead); )XI[hVUA  
} X1o",,N^M  
catch(Exception e){e.printStackTrace ();} 7*:zN  
} ]8$8QQc<<5  
} ;\MWxh,K  
XqH@3Ehk  
^W |YE72Y  
//打印回应的头信息 'Waa zk[@O  
public void logResponseHead(HttpURLConnection con) K;K0D@>]HR  
{ X+vKY  
for(int i=1;;i++) ;?h[WIy  
{ LG}{ibB  
String header=con.getHeaderFieldKey(i); kR]P/4r  
if(header!=null) q8 v iC|  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z 4u&#.bU  
Utility.log(header+" : "+con.getHeaderField(header)); <T 2O^  
else x6ghO-s  
break; j#HXuV6  
} }1a}pm2p  
} ["Zvwes#7  
.#EU@Hc  
\S}/2]* 1  
public void splitterStop() zAgX{$/Fg  
{ Z0gtliJ@  
bStop = true; ;QI9OcE@/  
} D 0Xl`0"'  
p1N}2]e  
IQqUFP$8g  
} *>fr'jj1$  
*^>"  h@J  
+VwQ=[y]  
/* hgU;7R,?ir  
**FileAccess.java ]jT}]9Q$  
*//文件访问(定位,写) 6<&~ R 3dQ  
package NetFox; KsDS!O  
import java.io.*; U}92%W?  
hBgE%#`s  
>?g@Nt8  
public class FileAccessI implements Serializable{ j^G=9r[,  
>%/x~UFc5  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yT ^x0?U  
RandomAccessFile oSavedFile; {16a P  
long nPos; 'g#%>  
)~2\4t4|g  
\J LGw1F  
public FileAccessI() throws IOException Bdo{zv&A  
{ y r (g/0  
this("",0); W"\~O"a  
} x&B&lFmo 8  
6w.E Sm  
vCa8`m  
public FileAccessI(String sName,long nPos) throws IOException 3%v)!dTa<^  
{ Vl.,e1)6  
oSavedFile = new RandomAccessFile(sName,"rw"); #W\}v(Ke  
this.nPos = nPos; ;i@S}LwL  
oSavedFile.seek(nPos); Yf0 KG  
} }[+uHR6L  
=Rd`"]Mnfb  
U`v2Yw3E  
public synchronized int write(byte[] b,int nStart,int nLen) "@ >6<(Ki  
{ +pd,gG?dW  
int n = -1; X[tt'5  
try{ s-p)^B  
oSavedFile.write(b,nStart,nLen); HxI6_>n^I  
n = nLen; J4bP(=w!  
} A?R`~*Q5  
catch(IOException e) 91OxUVd  
{ 2z>-H595az  
e.printStackTrace (); ;"dX]":  
} zlMh^+rMX  
.n:Q~GEL  
sXVl4!=l6  
return n; \Vc[/Qp7Bb  
} rr# nBhh8  
Pps$=`  
"i&)+dr-  
} B{Q}^Mcxy  
<rC%$tr  
G,C`+1$*  
/* 5 -i,Tx&:  
**SiteInfoBean.java ~ l}f@@u  
*/ !y_FbJ8KC  
package NetFox; 9xA4;)36  
Hf4_zd  
{Y~>&B5  
public class SiteInfoBean { }`=7%b`-?  
e=;A3S  
CR4O#f8\  
private String sSiteURL; //Site's URL Avx`  
private String sFilePath; //Saved File's Path i'f w>-0  
private String sFileName; //Saved File's Name Jn+-G4h$  
private int nSplitter; //Count of Splited Downloading File ?Q:SVxzUd  
w=KfkdAJ*/  
sx?IIFF  
public SiteInfoBean() - 2)k!5X=  
{//nSplitter的缺省值为5 pRQ7rT',v  
//default value of nSplitter is 5 <]Td7-n  
this("","","",5); TV`1&ta  
} 99yWUC,  
 3IxC@QR  
t/|0"\ p  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gIo\^ktW  
{ aM5]cc%  
sSiteURL= sURL; ?/|Xie  
sFilePath = sPath; @$ 7 GrT  
sFileName = sName; @=kg K[t 9  
this.nSplitter = nSpiltter; ky2]%cw  
?:r?K|Ku  
=lAjQt  
} u X,n[u  
L{/% "2>  
O Z ./suR)  
public String getSSiteURL() jNj;#C)  
{ UJO3Yn  
return sSiteURL; etX@z'H  
} ,Zmjw@ w  
)N 3^r>(e<  
TcZ.5Oe6h#  
public void setSSiteURL(String value) >pu4G+M  
{ k4Q>J,k  
sSiteURL = value; HV%/baX]  
} xPZ>vCg  
{aAd (~YZ  
1ksFxpE  
public String getSFilePath() X]y:uD{  
{ b8d0]YS  
return sFilePath; q,Gymh;  
} <7P[)X_  
97liSd  
^J]&($-  
public void setSFilePath(String value) `W86]ut[  
{ : UeK0  
sFilePath = value; *)K\&h<{  
} 1L,L/sOwB&  
R-%6v2;ry  
$0$sM/%  
public String getSFileName() NP;W=A F  
{ um%_kX  
return sFileName; 5L3+KkX@  
} ^PEw#.WG  
"Z&.m..gc  
v,i|:;G  
public void setSFileName(String value) 4jXo5SkEJ  
{ & /8Tth86  
sFileName = value; gqS9{K(f  
} 0+SDFh  
tWn dAM(U7  
a&>NuMDI  
public int getNSplitter() +q&Hj|;8r  
{ SnE^\I^O  
return nSplitter; ?^voA.Bv<  
} d,GOP_N8I  
|Gic79b  
X['9;1Xr  
public void setNSplitter(int nCount) 6f +aGz  
{ f<8Hvumw  
nSplitter = nCount; lpG%rN!  
} ^/BGOBK  
} k6CXuU  
;VE y{%nF  
m* m),mZ"  
/* >Y>R1b%  
**Utility.java 811>dVq3/  
*/ #gbB// <  
package NetFox; 2.3_FXSt  
`XxnQng  
EHUx~Q   
public class Utility { gsL=_# ?  
w0!$ow.l  
BwT[SI<Sg  
public Utility() Jk*cuf `rq  
{ @` KYgjjH  
, ;,B7g  
l@);U%\pS  
} .D W>c}1  
o-6d$c}{f  
//线程睡眠 `<9>X9.+  
public static void sleep(int nSecond) LGt>=|=bj  
{ c`<2&ke  
try{ 3y)\dln  
Thread.sleep(nSecond); PCl5,]B}  
} dJR[9T_OF  
catch(Exception e) sqKx?r72  
{ vIpL8B86a  
e.printStackTrace (); VKttJok1  
} ) lUS'I  
} ^Wld6:L{I  
tLu&3<%  
//日志 E7$&:xqx  
public static void log(String sMsg) [[|#}D:L  
{ V}V->j*  
System.err.println(sMsg); vK!`#W`X  
} *s4|'KS2o  
[Vs\r&qL  
iaL@- dg  
public static void log(int sMsg) ~ YH?wdT  
{ E`TZ:W]r,  
System.err.println(sMsg); @6UtnX'd  
} a/ A c^!(  
} !R8%C!=a  
R&|.Lvmc/  
MtJ-pa~n  
/* :{a< ~n`  
**TestMethod.java pyhXET '  
*/ >W>rhxU  
package NetFox; }r,M (Zr  
h:fiUCw  
[e><^R*u  
public class TestMethod { 9d"*Z%!j  
JX0M3|I=  
ox&5} &\  
public TestMethod() 3%*igpj\)  
{ ///xx/weblogic60b2_win.exe z3a GK  
try{ %"`p&aE:  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PIH\*2\/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1h@qcom9K_  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @JGmOwZ  
fileFetch.start(); $5pCfW8>  
} ehW[LRtq  
catch(Exception e){e.printStackTrace ();} qcs) p  
_UVpQ5pN  
ob>)F^.iS  
} eB~\~@  
 u 8o!  
JwMRquQv  
public static void main(String[] args) @V:K]M 5  
{ q=t!COS  
new TestMethod(); O=A R`r#u  
} g}%ODa !H  
} ;7\Fx8"s[  
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