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http断点续传简单实现(java)

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/* J,iS<lV_  
**SiteFileFetch.java Y -yozt  
*/ .r ,wc*SF  
package NetFox; |ry![\  
import java.io.*; #:B14E  
import java.net.*; #VM+.75o1  
]>v C.iYp  
 }?eO.l{  
public class SiteFileFetch extends Thread { 0tz7^:|D  
hFMJDGCw>Q  
YR'dl_  
SiteInfoBean siteInfoBean = null; //文件信息Bean NL^;C3u  
long[] nStartPos; //开始位置 $ jkzm8{W  
long[] nEndPos; //结束位置 scc+r  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 SEKR`2Zz,  
long nFileLength; //文件长度 <z.Y#{p?k  
boolean bFirst = true; //是否第一次取文件 *A&A V||q  
boolean bStop = false; //停止标志 v[Mh[CyB  
File tmpFile; //文件下载的临时信息 'hGUsi  
DataOutputStream output; //输出到文件的输出流 b6%[?k  
tDC?St1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }H Ct=W`  
public SiteFileFetch(SiteInfoBean bean) throws IOException FOyANN'  
{ ;W 3#q:  
siteInfoBean = bean; Yt!o Hn  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "cZ){w  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iFOa9!_0n  
if(tmpFile.exists ()) >b7Yk)[%  
{ 1b=,lm  
bFirst = false; q _INGCJ  
read_nPos(); \? n<UsI  
} mI,a2wqi  
else +xL' LC x  
{ j'uzjs[  
nStartPos = new long[bean.getNSplitter()]; iBPIj;,  
nEndPos = new long[bean.getNSplitter()]; Z!+n/ D-1  
} u0Bz]Ux/Q  
5E#8F  
Eo`'6 3  
dDbH+kqO  
} kp-`_sDg  
M?00n< vM  
+<T361eyY  
public void run() YJ !jdE}  
{ |;(>q  
//获得文件长度 .wO-2h{Q  
//分割文件 V 7oE\cxr  
//实例FileSplitterFetch 0}` 0!Kv  
//启动FileSplitterFetch线程 c;,-I  
//等待子线程返回 3V]08  
try{ q:1n=i Ei  
if(bFirst) m f\tMik<  
{ '=+gwe M  
nFileLength = getFileSize(); A6 I^`0/  
if(nFileLength == -1) zWrynJ}s  
{ G '%ZPh89  
System.err.println("File Length is not known!"); L@S1C=-/  
} -;O"Y?ME  
else if(nFileLength == -2) O YfRtfE  
{ gL &)l!2Y  
System.err.println("File is not access!"); Us\Nmso z  
} OD~yIV  
else F;MACu;x  
{ BxiR0snf0q  
for(int i=0;i<nStartPos.length;i++) vs{VRc  
{ VFK]{!C_  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @zJiR{Je-U  
} .7+"KP:  
for(int i=0;i<nEndPos.length-1;i++) g77:92  
{ /vPr^Wv  
nEndPos = nStartPos[i+1]; xP 7mP+D  
} Q]]M;(  
nEndPos[nEndPos.length-1] = nFileLength; RJ-J/NhWyI  
} sT,*<^  
} w3;T]R*  
Z?qc4Cg  
+1a2Un  
//启动子线程 "$3~):o  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s~A:*2\  
for(int i=0;i<nStartPos.length;i++) #+ {%>f  
{ d>0 j!+s  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R8Dn GR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _`Dz%(c  
nStartPos,nEndPos,i); Hn]6re  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D7Ds*X`!l  
fileSplitterFetch.start(); KDr)'gl&  
} E?jb?  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gb.}af#v  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (\4YBaGd  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uFG ;AY|  
nEndPos = " + nFileLength); qxHsmGV  
// fileSplitterFetch[nPos.length-1].start(); BPu>_$C  
zX8{(  
&D`$YUl@  
//等待子线程结束 b{,vZhP-  
//int count = 0; [bEm D  
//是否结束while循环 .VkLF6  
boolean breakWhile = false; ):V)Hrq?x  
ah!fQLMH  
CYNpbv  
while(!bStop) %p};Di[V  
{ 7mYBxE/  
write_nPos(); (N{  
Utility.sleep(500); Jh%k:TrBm  
breakWhile = true; |RI77b:pX  
aIE\B4w  
&_Z8:5e  
for(int i=0;i<nStartPos.length;i++) y9Q"3LLic`  
{ u"zQh|  
if(!fileSplitterFetch.bDownOver) WhL 1OG  
{ Q?Uk%t\hwc  
breakWhile = false; 0.!Q 4bhD  
break; v?h8-yed  
} |9 4xRC  
} l5_%Q+E_  
if(breakWhile) 7@i2Mz/eV  
break; wqp(E+&  
dUpOg{I.x  
~{s7(^ P  
//count++; qzu%Pp6If  
//if(count>4) LWP&Si*j  
// siteStop(); I\ y>I?X  
} :aMp,DfM]P  
d*<goBd  
bq` 0$c%hN  
System.err.println("文件下载结束!"); D\V (r\i  
} Q_n9}LanP  
catch(Exception e){e.printStackTrace ();} ]i pltR7k  
} {~:F1J~=  
x^ ]1m%  
K\>CXa  
//获得文件长度 Z=P=oldH  
public long getFileSize() #-u?+Nk/  
{ & pS5_x  
int nFileLength = -1; Fh$Xcz~i  
try{ ' 5"`H>[  
URL url = new URL(siteInfoBean.getSSiteURL()); IK^jzx   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GPnSdGLC  
httpConnection.setRequestProperty("User-Agent","NetFox"); ceqYyVy  
p![CH  
~2*8pb 4  
int responseCode=httpConnection.getResponseCode(); H@xIAL  
if(responseCode>=400) y|@=j~}Zq  
{ SpUcrK;1  
processErrorCode(responseCode); f<0nj?  
return -2; //-2 represent access is error  ,M&[c|  
} y(RK|r  
3#H x^H  
N;6WfdA-  
String sHeader; ]gQ4qu5  
=1"8ua  
xdH*[  
for(int i=1;;i++) K-nf@o+  
{ v+|N7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W@x UR-}51  
//Utility.log(in.readLine()); ZrFC#wJb  
sHeader=httpConnection.getHeaderFieldKey(i); w(9.{zF|vQ  
if(sHeader!=null) 8vcV-+x  
{ Dyj5a($9"{  
if(sHeader.equals("Content-Length")) -)tu$W*  
{ \Podyh/;?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dSb|hA}@  
break; [S/]Vk|4  
} l*]*.?m/5  
} B&`hvR  
else RYaf{i`  
break; !#nlWX :~  
}  (Ia}]q  
} <;.Zms${@  
catch(IOException e){e.printStackTrace ();} +t R6[%  
catch(Exception e){e.printStackTrace ();} z2&SZ.mk  
h&Ehp   
d"|XN{  
Utility.log(nFileLength); <m80e),~  
D!~-53f@  
$@t-Oor;  
return nFileLength; M? oK@i  
} .Mw'P\GtM  
Mrp'wF D  
elZ?>5P$}  
//保存下载信息(文件指针位置)  XGEAcN  
private void write_nPos() PY.c$)az>  
{ 8| zR8L  
try{ B3'qmi<  
output = new DataOutputStream(new FileOutputStream(tmpFile)); d(w $! $"h  
output.writeInt(nStartPos.length); \CL |=8[2  
for(int i=0;i<nStartPos.length;i++) N G1]!Vz5  
{ |8h<Ls_  
// output.writeLong(nPos); F9ry?g=h  
output.writeLong(fileSplitterFetch.nStartPos); ~<3qsA..  
output.writeLong(fileSplitterFetch.nEndPos); :*e0Z2=  
} #"6(Q2| l  
output.close(); phUno2fH  
} r+0"1\f3  
catch(IOException e){e.printStackTrace ();} ]6</{b  
catch(Exception e){e.printStackTrace ();} I~MBR2$9  
} %lV&QQa  
YcGSZ0vQ  
Ywt_h;:  
//读取保存的下载信息(文件指针位置) Y*O7lZuF%  
private void read_nPos() A L}c-#GG  
{ z?h\7 R  
try{ y%=\E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1^R@X  
int nCount = input.readInt(); oDx*}[/  
nStartPos = new long[nCount]; $ # @G!  
nEndPos = new long[nCount]; Q$W0>bUP  
for(int i=0;i<nStartPos.length;i++) R,/?p  
{ )dG7 $,g  
nStartPos = input.readLong(); \^?BC;s^C  
nEndPos = input.readLong(); ];^A8?  
} ^M  PU?k  
input.close(); Qwk  
} O:RPH{D  
catch(IOException e){e.printStackTrace ();} d37l/I  
catch(Exception e){e.printStackTrace ();} E*7B5  
} ?y'KX]/  
,$mnD@)  
t'_Hp},  
private void processErrorCode(int nErrorCode) b'O>&V`  
{ [sTr#9Z  
System.err.println("Error Code : " + nErrorCode);  e1S |&W8  
} S,lJ&Rsu  
Jj|HeZ1C f  
,`G8U/  
//停止文件下载 HW"|Hm$Y(  
public void siteStop() 22`W*e@6h  
{ NM/?jF@j*  
bStop = true; kW4/0PD  
for(int i=0;i<nStartPos.length;i++) gf2l19aP  
fileSplitterFetch.splitterStop(); &iR>:=ks N  
ly}6zOC\  
A0cC)bd&  
} fr;>`u[;  
} J8J~$DU\Gv  
//负责部分文件的抓取 ?zQ\u{]=  
**FileSplitterFetch.java syA*!Up  
*/ 9loWh5_1Z  
package NetFox; 4gb2$"!  
`ndesP  
7qA0bUee5  
import java.io.*; U voX\  
import java.net.*; dZIAotHN:  
x:88E78  
Y]P'; C_eP  
public class FileSplitterFetch extends Thread { ?5Wjy  
#gMMh B=  
>t)vQ&:;u  
String sURL; //File URL ,icgne1j  
long nStartPos; //File Snippet Start Position sczN0*w&C  
long nEndPos; //File Snippet End Position _~&6Kb^*  
int nThreadID; //Thread's ID A)kx,,[  
boolean bDownOver = false; //Downing is over LUl6^JU  
boolean bStop = false; //Stop identical =zDU!< U  
FileAccessI fileAccessI = null; //File Access interface Yew n  
}Xr-xh \v  
4[ M!x  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bvuoGG*  
{ 6b~Zv$5^Y-  
this.sURL = sURL; TUIj-HSe  
this.nStartPos = nStart; |Up+Kc:z/n  
this.nEndPos = nEnd; 0Jm6 r4s?  
nThreadID = id; 8V>j-C  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8;ke,x  
} WW{5[;LYiB  
\{t#V ~  
yQ}$G ,x  
public void run() k<Z^93 S  
{ T1m"1Q  
while(nStartPos < nEndPos && !bStop) klxVsx%I{G  
{ SG_^Rd9 D  
<gF=$u|}3[  
=@AWw:!:,  
try{ !Y>lAxd  
URL url = new URL(sURL); Yz=(zj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 15+>W4v  
httpConnection.setRequestProperty("User-Agent","NetFox"); gELku .  
String sProperty = "bytes="+nStartPos+"-"; n1m[7s.[&  
httpConnection.setRequestProperty("RANGE",sProperty); OSQZ5:g|  
Utility.log(sProperty); 1 0lvhzU  
Ehi)n)HhG"  
=.(yOUI  
InputStream input = httpConnection.getInputStream(); ye:pGa w  
//logResponseHead(httpConnection); `E+)e?z  
&lbxmUeU  
px %xoY  
byte[] b = new byte[1024]; Xf!@uS6<X  
int nRead; NUbw]Y90~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u~[HC)4(0  
{ fuSfBtLPR#  
nStartPos += fileAccessI.write(b,0,nRead); ^e:C{]S=  
//if(nThreadID == 1) +%Q:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,A`d!{]5  
} $}V<U m  
1 rKKph  
&E0L7?l  
Utility.log("Thread " + nThreadID + " is over!"); 6E/>]3~!  
bDownOver = true; Zu`; S#Y  
//nPos = fileAccessI.write (b,0,nRead); k4fc 5P  
} .) uUpY%K^  
catch(Exception e){e.printStackTrace ();} B4yU}v  
} *GleeJWz  
} 74Xk^  8  
wI><kdz  
 UhN16|x  
//打印回应的头信息 ,@kD9n5#  
public void logResponseHead(HttpURLConnection con) 1^XuH('  
{ ' N^\9X0  
for(int i=1;;i++) vw5f.8T;w  
{ Z:DEET!c'k  
String header=con.getHeaderFieldKey(i); RO[Ko-m|/N  
if(header!=null) ^]l^q'?>:  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PPk\W7G  
Utility.log(header+" : "+con.getHeaderField(header)); <~;;iM6  
else '{dduHo  
break; %E#OUo[y/  
} #<0Yx9Jh.  
} 59mNb:<  
K~ ,| ~  
ZycV?ob8}  
public void splitterStop() s3qWTdM  
{ nfpkWyIu{  
bStop = true; `q|&;wP.  
} mAMi-9  
**_`AM~  
D,q=?~  
} g?` g+:nug  
.w2QiJ  
Go~bQ2*'(/  
/* BC*vG=a  
**FileAccess.java _nu,ks+  
*//文件访问(定位,写) Tlrr02>B{  
package NetFox; IN=pki |.  
import java.io.*; u$ [R>l9  
+13h *  
Fx,08  
public class FileAccessI implements Serializable{ ^?PU:eS  
>2h|$6iWP  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X8~dFjhX  
RandomAccessFile oSavedFile; *uHL'Pe;m  
long nPos; uo0g51%9  
,: g.B\'Q  
$$ %4,\{l  
public FileAccessI() throws IOException y_O[r1MF  
{ j !^Tw.Ty  
this("",0); {Hncm  
}  :VwU2  
2WQKj9iyN  
].F7. zi  
public FileAccessI(String sName,long nPos) throws IOException @_"B0$,-i  
{ 1=BDqSZ@9  
oSavedFile = new RandomAccessFile(sName,"rw"); Td#D\d\R  
this.nPos = nPos; @P=St\;VP  
oSavedFile.seek(nPos); OS8 ^mC  
} I)#=#eI* :  
iEx.BQ+  
&:}e`u@5|  
public synchronized int write(byte[] b,int nStart,int nLen) kk]f*[Zi5  
{ gXr"],OM;  
int n = -1; @3`:aWda  
try{ Y `4AML  
oSavedFile.write(b,nStart,nLen); 1'ne[@i^/  
n = nLen; AA][}lU:5  
} z_qy >  
catch(IOException e) ~\= VSwJ  
{ [A$5~/Q{U1  
e.printStackTrace (); &v!=\Fig4  
} pR_cI]{=SA  
[ZwZGAP  
yM dEH-?/  
return n; `$og]Dn;  
} zNSix!F  
iVq4&X_x  
").MU[q%Y  
} *M5 : \+  
NGYliP,.6  
>! +.M9  
/* xlPUu m-o  
**SiteInfoBean.java TDI8L\rr  
*/ wMy$T<:   
package NetFox; m"Y;GzqQl  
xml@]N*D#E  
4d&#NP  
public class SiteInfoBean { Ol,;BZHc\  
36>pa  
z0J$9hEg89  
private String sSiteURL; //Site's URL ^NJ]~h{n$  
private String sFilePath; //Saved File's Path Zgp]s+%E  
private String sFileName; //Saved File's Name Y" 9 o  
private int nSplitter; //Count of Splited Downloading File rkhQoYZ[  
dz/' m7  
@|Z:7n6S  
public SiteInfoBean() :xw2\:5~0  
{//nSplitter的缺省值为5 O v3W;jD  
//default value of nSplitter is 5 34VyR a  
this("","","",5); -q7A\8C  
} K/RQ-xd4  
[?)=3Pp  
216+ tX5Z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VM{`CJ2  
{ j]7|5mC78  
sSiteURL= sURL; [vki^M5i|Z  
sFilePath = sPath; u#5/s8  
sFileName = sName; :LRR\v0HM  
this.nSplitter = nSpiltter; \RN,i]c-g/  
-_=0PW5{  
MLg<YL  
} pT]M]/y/:  
& pwSd  
#!p=P<4M  
public String getSSiteURL() 6cof Zc$  
{ >}QRMn|@H  
return sSiteURL; {#q']YDe`  
} y e!Bfz>  
EM/NT/  
f@l6]z{.L  
public void setSSiteURL(String value) ~ZU;0#  
{ C("PCD   
sSiteURL = value; A7U'>r_.  
} CG'NC\x5  
R`=3lY;  
3nuf3)  
public String getSFilePath() Lm+!/e  
{ ) Kfk\  
return sFilePath; <B6@q4Q  
} `NA[zH,w3  
D^Dm, -  
<'A>7M~h?*  
public void setSFilePath(String value) C%d 4ItB >  
{ 7}bjJR "  
sFilePath = value; ];Whvdnv  
} JV'd!5P  
/=Ug}%.  
Q0~5h?V'  
public String getSFileName() 2=ZR}8}9Q:  
{ Z+ubc"MVb  
return sFileName; Cus=UzL  
} m%V+px  
ZCPK{Ru QE  
bHlG(1uf  
public void setSFileName(String value) qG"|,bA  
{ }]vj"!?a  
sFileName = value; }@yvw*c  
} +C7 1".i-  
7=XQgbY/  
 l|`FW  
public int getNSplitter() XuJwZN!(  
{ 5_Yv>tx  
return nSplitter; lEi,duS)  
} oTtmn, T  
vl$! To9R"  
Wm:3_C +j  
public void setNSplitter(int nCount) Pb?H cg  
{ mm$D1=h{|  
nSplitter = nCount; YVVX7hB  
} 7ka^y k@Q  
} OXDlwbwL  
))c;DJc  
lp[3z& u  
/* c?) pn9  
**Utility.java 6A M,1  
*/ , >Y. !  
package NetFox; _yjM_ALjo  
T\c;Ra  
?>MD/l(l  
public class Utility { DHpU?;|3  
t )Z2"_5  
]SrKe-*:U  
public Utility() [e)81yZG>  
{ 80$P35Q"  
yP0P-8  
iM2 EEC  
} fEs957$  
`'Ta=kd3  
//线程睡眠 ;t%L (J  
public static void sleep(int nSecond) |PH]0.m5  
{ !~UI~-i'  
try{ OfTcF_%  
Thread.sleep(nSecond); xmKa8']x  
} j-gLX  
catch(Exception e) ;TSnIC)c  
{ CkoPno  
e.printStackTrace (); 6uDA{[OH  
} 9?D7"P+  
} s cR-|GuZ  
X1<)B]y  
//日志 Y'f I4  
public static void log(String sMsg) 'G(N,vu[@  
{ $ajw]2kx  
System.err.println(sMsg); y NV$IN%  
} ?Z4& j'z<  
};9dd3X  
 %W"\  
public static void log(int sMsg) :Tuy]]k  
{ gZM{]GQ  
System.err.println(sMsg); L:Wy- Z  
} 4NR,"l)  
} miS+MK"  
{J})f>x<xM  
%>I!mD"X\  
/* } Q1$v~  
**TestMethod.java  p<*-B  
*/ 1)_f9GR  
package NetFox; TG?;o/  
?P`wLS^;  
5[l3]HOO  
public class TestMethod { >[|:cz  
#*S/Sh?Q  
1bzPBi  
public TestMethod() ;ok];4`a  
{ ///xx/weblogic60b2_win.exe 5B'-&.Aj+  
try{ %c^]Rdl  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6FEtq,;0w  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /oiAAB27  
SiteFileFetch fileFetch = new SiteFileFetch(bean); JS(KCY9  
fileFetch.start(); hN\E8"To  
} wT*N{).  
catch(Exception e){e.printStackTrace ();} .6O>P2m]a_  
Va=0R   
AN: ,t(w  
} f~Kln^  
! FHNKh  
zN5i}U=|r  
public static void main(String[] args) e}[$ =  
{ 4] ?  
new TestMethod(); oPa2GW8  
} *qOo,e  
} hNx`=D9[7  
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