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http断点续传简单实现(java)

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/* K19/M1~  
**SiteFileFetch.java $HF. 02{|  
*/ ]@Y8! ,  
package NetFox; b4Br!PL@G  
import java.io.*; h$)(-_c3  
import java.net.*; ah1d0e P  
G+stt(k:  
mM!'~{r[-  
public class SiteFileFetch extends Thread { jGl8y!aM  
U s86.@|  
K]Q#B|_T  
SiteInfoBean siteInfoBean = null; //文件信息Bean ];Z)=y,vM  
long[] nStartPos; //开始位置 <gF=$u|}3[  
long[] nEndPos; //结束位置 p @&>{hi@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 j2c -01}  
long nFileLength; //文件长度 S_/9eI~X  
boolean bFirst = true; //是否第一次取文件 <`i " 5`J  
boolean bStop = false; //停止标志 >G$8\&]j  
File tmpFile; //文件下载的临时信息 Bw;sg;  
DataOutputStream output; //输出到文件的输出流 (MY#;v\AYE  
n1m[7s.[&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) FB9PIsFS  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;,[6 n|M  
{ z6ISJb  
siteInfoBean = bean; DZ92;m  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); k"&l o h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 'DO^($N  
if(tmpFile.exists ()) oG M Ls  
{ A-^[4&rb  
bFirst = false; Q1jU{  
read_nPos(); N+ZDQa[  
} )uC],CbW{  
else T6h-E^Z  
{ ."&,_F  
nStartPos = new long[bean.getNSplitter()]; {e\Pd!D?|  
nEndPos = new long[bean.getNSplitter()]; lPx4=O  
} /ts=DxCC;  
rl4B(NZi}  
7zXFQ|TP  
bO 2>ced  
} GmP)"@O](;  
0{^vqh.La  
1 rKKph  
public void run() &E0L7?l  
{ 6E/>]3~!  
//获得文件长度 }IO<Dq=[  
//分割文件 Se<]g$eK?5  
//实例FileSplitterFetch jWJq[l  
//启动FileSplitterFetch线程 0<_|K>5dS|  
//等待子线程返回 :,g nOfV=  
try{ m^0r9y,  
if(bFirst) Oo |*q+{  
{ w F6ywr  
nFileLength = getFileSize(); mbB,j~;^6H  
if(nFileLength == -1) g\S@@0T{0  
{ (DJLq  
System.err.println("File Length is not known!"); JBfDz0P  
} mR@|]T  
else if(nFileLength == -2) d0Xb?- }3M  
{ TG7Ba[%  
System.err.println("File is not access!"); _;(`u!@/{  
} ]Q,;5>#W  
else Ls{z5*<FM  
{ b&[9m\AX`  
for(int i=0;i<nStartPos.length;i++) oFM\L^Y?$$  
{ psyxNM=dN#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 7ksh%eV  
} .] mYpz  
for(int i=0;i<nEndPos.length-1;i++) 9qN4f8R  
{ oJa6)+b(3  
nEndPos = nStartPos[i+1]; YL-/z4g  
} U/F<r3.`#  
nEndPos[nEndPos.length-1] = nFileLength; _OV\W'RrA  
} @)PA9P |  
} 6(awO2{BP  
**_`AM~  
D,q=?~  
//启动子线程 g?` g+:nug  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t\~lGG-p  
for(int i=0;i<nStartPos.length;i++) i)9}+M 5  
{ ;,P-2\V/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QR4rQu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &7z79#1NS  
nStartPos,nEndPos,i); U<,@u,_Ja  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2 gz}]_  
fileSplitterFetch.start(); ]@X5'r"  
} z@;]Hy  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e~R; 2bk  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .{sKEVK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *z[G+JX  
nEndPos = " + nFileLength); ^?PU:eS  
// fileSplitterFetch[nPos.length-1].start(); 88}+.-3t$  
>dKK [E/[d  
'f&o%5]  
//等待子线程结束 $$ %4,\{l  
//int count = 0; y_O[r1MF  
//是否结束while循环 n,sf$9"  
boolean breakWhile = false; "hwg";Z$n  
f!6oW(r-L  
Y.` {]rC  
while(!bStop) Y<|!)JLB2  
{ 0\v98g<[+  
write_nPos(); )006\W|t9  
Utility.sleep(500); W}m-5L  
breakWhile = true; ! |SPOk  
qu]ch&"?U  
b`"E(S/  
for(int i=0;i<nStartPos.length;i++) I)#=#eI* :  
{ iEx.BQ+  
if(!fileSplitterFetch.bDownOver) <@i.~EL  
{ v{{Cj83S+  
breakWhile = false; L%](C  
break; u8ofgcFYE  
} ^0"^Xk*  
} Ow7NOhw  
if(breakWhile) RC 7|@a  
break; +|}R^x`z  
:g)0-gN   
g8^\|  
//count++; W>C!V  
//if(count>4) h(}$-'g  
// siteStop(); dWHl<BUm  
} v|5:;,I  
` nBCCz'Y!  
n Q|4.e;  
System.err.println("文件下载结束!"); zNSix!F  
} iVq4&X_x  
catch(Exception e){e.printStackTrace ();} @L^Fz$Sx  
} .d< +-w2Mu  
m-f"EFmP  
fR_ jYP 1  
//获得文件长度 GwiG..Y]&  
public long getFileSize() HI/]s^aL  
{ 1I({2@C  
int nFileLength = -1; G| 7\[!R  
try{ 89@\AjI  
URL url = new URL(siteInfoBean.getSSiteURL()); 8N<0|u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W{E2 2J}  
httpConnection.setRequestProperty("User-Agent","NetFox"); H /Idc,*  
IV{,'+hT  
JFaxxW  
int responseCode=httpConnection.getResponseCode(); [NcS[*qp  
if(responseCode>=400) ;t!n%SnK9!  
{ ,h21 h?6  
processErrorCode(responseCode); e&[gde(  
return -2; //-2 represent access is error qW]gp7jK4  
}  >)ZX  
Enee\!@v  
~;St,Fw<<  
String sHeader; +EJwWDJ!%  
#PnuR2s7.  
S,T?(lSl  
for(int i=1;;i++) }.Eq_wP<  
{ WqN=  D5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \m-fLX  
//Utility.log(in.readLine()); %M8Egr2|0  
sHeader=httpConnection.getHeaderFieldKey(i); a%*l]S0z"  
if(sHeader!=null) R'a%_sACj>  
{ wu?ahNb.`Y  
if(sHeader.equals("Content-Length")) AH`n  
{ i^P@?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z J(/cD  
break; 97:1L4w.(  
} * d6[k Y  
} wUzQ`h2  
else "%~\kJ(G  
break; PoMkFG6  
} ps0wN%tA  
} Q,Tet&in )  
catch(IOException e){e.printStackTrace ();} ]2G5ng' @  
catch(Exception e){e.printStackTrace ();} 6cof Zc$  
>}QRMn|@H  
{#q']YDe`  
Utility.log(nFileLength); y e!Bfz>  
'B}pIx6k~  
tf64<j6  
return nFileLength; D|I(2%aC  
} RAR0LKGX  
7t-j2 n`<  
4X7y}F.J  
//保存下载信息(文件指针位置) Wz$%o'OnC  
private void write_nPos() %VYQz)yW  
{ G)gf +)W  
try{ <B6@q4Q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); CCKg,v  
output.writeInt(nStartPos.length); WtI1h`Fo  
for(int i=0;i<nStartPos.length;i++) H3{x; {.b  
{ :QgC Zq  
// output.writeLong(nPos); Mq) n=M  
output.writeLong(fileSplitterFetch.nStartPos); E#"QaI8`  
output.writeLong(fileSplitterFetch.nEndPos); \C.%S +u  
} 1A^iUC5)  
output.close(); A9PXu\%y  
} q0WW^jwQ  
catch(IOException e){e.printStackTrace ();} PJj{5,#@3  
catch(Exception e){e.printStackTrace ();} =/=x"q+X  
} 2{s ND  
J<DV7zV  
b~06-dk1  
//读取保存的下载信息(文件指针位置) j`Lf/S!}  
private void read_nPos() iHjo3_g)n  
{ +C7 1".i-  
try{ 7=XQgbY/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  l|`FW  
int nCount = input.readInt(); }yqRz6=YB  
nStartPos = new long[nCount]; J#*Uf>5NY  
nEndPos = new long[nCount]; `7jm   
for(int i=0;i<nStartPos.length;i++) Fk D  
{ mOwgk7s[ J  
nStartPos = input.readLong(); :NU-C!eT  
nEndPos = input.readLong(); s# w+^Mw$  
}  N>`+{  
input.close(); "M6a_rZ2W  
} #1Mk9sxo  
catch(IOException e){e.printStackTrace ();} EZ #UdK_  
catch(Exception e){e.printStackTrace ();} *lv)9L+0  
} @RotJl/>  
etf ft8  
La%\- o  
private void processErrorCode(int nErrorCode) 7UHqiA`L  
{ ?97MW a   
System.err.println("Error Code : " + nErrorCode); Z_' %'&Y  
} q?z6|]M|u  
*pP"u::S  
0kgK~\^,.O  
//停止文件下载 cb&y8!ci~  
public void siteStop() t )Z2"_5  
{ 5X&<+{bX  
bStop = true; Bir }X  
for(int i=0;i<nStartPos.length;i++) R+]p -NI^  
fileSplitterFetch.splitterStop(); %9M; MK  
r0G#BPgdR  
d_J?i]AP|'  
} DjOFfD\MF  
} "b%hAdR  
//负责部分文件的抓取 2a.NWJS  
**FileSplitterFetch.java wlqV1.K  
*/ u#p1W|\4  
package NetFox; EC1q#;:  
,2JqX>On>Y  
GQqw(2Ub}  
import java.io.*; *p?b"{_a  
import java.net.*; q`1t*<sk  
{#QFDA  
2`5(XpYe  
public class FileSplitterFetch extends Thread { sxL;o >{  
]wne2WXE  
d1e'!y}R5  
String sURL; //File URL &o"Hb=k<  
long nStartPos; //File Snippet Start Position 5K'EuI)  
long nEndPos; //File Snippet End Position 7i{Rn K6*  
int nThreadID; //Thread's ID @usQ*k  
boolean bDownOver = false; //Downing is over +azPpGZ=  
boolean bStop = false; //Stop identical PB>p"[ap4  
FileAccessI fileAccessI = null; //File Access interface ~b\7 qx_a9  
JoW*)3Z  
_zh}%#6L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UShn)3F  
{ '5ky<  
this.sURL = sURL; XyS#6D  
this.nStartPos = nStart; Y@eHp-[  
this.nEndPos = nEnd; H[@}ri<  
nThreadID = id; R'dF<&Kj|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &4*&L.hPM^  
} CcY.8|HT  
%>I!mD"X\  
!P@u4FCs  
public void run() yfTnj:Fz  
{ n_Um)GI>  
while(nStartPos < nEndPos && !bStop) u;J=g  
{ EfDo%H^!j  
?; )(O2p  
vCH>Fj"7  
try{ q,nj|9z V  
URL url = new URL(sURL); "]c:V4S#`A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6./&l9{h+  
httpConnection.setRequestProperty("User-Agent","NetFox"); EVO5+  
String sProperty = "bytes="+nStartPos+"-"; FGwz5@|E  
httpConnection.setRequestProperty("RANGE",sProperty); DP^{T/G  
Utility.log(sProperty); )\mklM9Z  
5mSXf"R^  
wT*N{).  
InputStream input = httpConnection.getInputStream(); mf}?z21vD  
//logResponseHead(httpConnection); 3tXtt@Yy  
O.rk!&N  
v@>hjie  
byte[] b = new byte[1024]; P]Gsc  
int nRead; oeIB1DaI  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XQj`KUO@  
{ 9q* sR1  
nStartPos += fileAccessI.write(b,0,nRead); Br#]FB|tD  
//if(nThreadID == 1) w-/bLg[L?$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s #L1:L  
} :\80*[=;Z  
#S<>+,Lk  
}GkEv}~t  
Utility.log("Thread " + nThreadID + " is over!"); nWXI*%m5  
bDownOver = true; BOwkC;Q[  
//nPos = fileAccessI.write (b,0,nRead); ~Ag !wj  
} ,?&hqM\  
catch(Exception e){e.printStackTrace ();} (3]7[h7  
} WDzov9ot  
} 7%7_i%6wP  
tm]75*?  
fiw~"2U  
//打印回应的头信息 B|extWwu  
public void logResponseHead(HttpURLConnection con) z[t$[Q g  
{ ybS7uo  
for(int i=1;;i++) J|xqfY@+  
{ a*SJHBB  
String header=con.getHeaderFieldKey(i); {+C>^b  
if(header!=null) QJ"B d`wc  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vpXS!o>/Sn  
Utility.log(header+" : "+con.getHeaderField(header)); 6bb=;  
else 5j ]}/Aq  
break; {xM%3  
} ~]"}s(J;  
} k(^zhET  
HwU \[f  
$wN'mY  
public void splitterStop() :eIB K  
{ !5A nr  
bStop = true; v0$6@K;M4G  
} 9MHb<~F  
ny=CtU!z  
(Mtc&+n{  
} GuDus2#+  
+,|-4U@dl  
Rb9Z{Clq>  
/* d9Q%GG0]  
**FileAccess.java 3[V|C=u0  
*//文件访问(定位,写) 5lU`o  
package NetFox; 9l,Gd  
import java.io.*; @L0wd>  
HvTi^Fb\a  
^2mXXAQf7^  
public class FileAccessI implements Serializable{ N}dJ)<(2~  
Kjf#uU.7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3i s .c)  
RandomAccessFile oSavedFile; ?L'k2J  
long nPos; U3za}3  
g` h>:5]  
x65e,'  
public FileAccessI() throws IOException @{ nT4{  
{ ,$}Q#q  
this("",0); hG ]jm  
} Pu9.Uwx  
F8=6!Qj  
Jp= (Q]ab  
public FileAccessI(String sName,long nPos) throws IOException Wc]Fg9E  
{ hqBwA1](a  
oSavedFile = new RandomAccessFile(sName,"rw"); BryMq !  
this.nPos = nPos; ntF(K/~Y  
oSavedFile.seek(nPos); SjJUhTb  
} FcWu#}.p}  
xv%}xeE V  
F;_;lRAb  
public synchronized int write(byte[] b,int nStart,int nLen) QU#/(N(U#T  
{ kh5V&%>?  
int n = -1; 3$kZu  
try{ XG [%oL  
oSavedFile.write(b,nStart,nLen); PAc~p8S  
n = nLen; Kp&d9e{ Yc  
} bZlAK)  
catch(IOException e) V2y[IeSQ  
{ ;{ezK8FJ}@  
e.printStackTrace (); $`5DGy?RU  
} q OXL(  
zCQv:.0L  
r;'!qwr  
return n; "*T)L<G  
} \UC4ai2MK  
O^<6`ku  
~kHir]jc  
} "ulaF+  
m&%N4Q~X>  
2MC\~"L<  
/* "E8!{  
**SiteInfoBean.java ydFY<Mb(o  
*/ 'Oc8[8   
package NetFox; NMDNls&)k  
4v!@9.!vQ  
%z2nas$$g  
public class SiteInfoBean { 1dq.UW\  
yO($KL +  
K4rr.f6  
private String sSiteURL; //Site's URL d-* 9tit  
private String sFilePath; //Saved File's Path V4"AFArI  
private String sFileName; //Saved File's Name z=xHk|+'  
private int nSplitter; //Count of Splited Downloading File 3}+/\:q*  
h1Lp:@:|  
5FzRusNiA  
public SiteInfoBean() Cse0!7_T  
{//nSplitter的缺省值为5 c`>\R<Z ]  
//default value of nSplitter is 5 dOhV`8l  
this("","","",5); wiVQMgi`  
} W@G[ gS\T  
_c&*'IY[V  
T'V(%\w  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )_=&)a1U  
{ Z:*U/_G  
sSiteURL= sURL; A`r9"([-A  
sFilePath = sPath; kgIWgk%  
sFileName = sName; ^DH*@M  
this.nSplitter = nSpiltter; vBpg6 fX  
~;+vF-]R  
MJb = +L  
} wx!*fy4hL  
V ;6M[ic}  
~L1O\V i  
public String getSSiteURL() Z^|C~lp;n  
{ bXfOZFzq)  
return sSiteURL; `8-aHPF-  
} 6?lg 6a/eO  
rNAu@B  
J'EK5=H  
public void setSSiteURL(String value) M;9+L&p=  
{ =6dKC_Q  
sSiteURL = value; 0 mQ3P.9  
} HB}gn2 .1&  
$7r wara  
`SW " RLS3  
public String getSFilePath() KCFwO'  
{ mx[^LaR>v  
return sFilePath; o`U\Nhq  
} VB#31T#q?  
? 1{S_  
@Otc$hj  
public void setSFilePath(String value) KC u6:)6'  
{ ^ZlV1G;/W@  
sFilePath = value; -7$'* V9$  
} {q)B@#p  
JXAyF6 $  
YUb,5Y0  
public String getSFileName() L,Nr,QC-  
{ >(rB[ZJ  
return sFileName; ^;3rdBprm  
} CJOl|"UyJ  
]aRD6F:L  
S=g-&lK  
public void setSFileName(String value) v6VhXV6$|  
{ i6CYD  
sFileName = value; Ak1)  
} ]mj+*l5  
55DzBV  
Vr1|%*0Tv  
public int getNSplitter() >l1Yhxd_0*  
{ IpJv\zH7  
return nSplitter; O)|4>J*B  
} Ltw7b  
<`3(i\-X  
@qDrTH]5  
public void setNSplitter(int nCount) @,&m`qzd+  
{ @>@Nu g2   
nSplitter = nCount; QL2y,?Mz7  
} B|=maz:_  
} aTm.10{^  
weV#%6=5\  
pCUOeQL(  
/* zrO|L|F&P  
**Utility.java ss{=::#  
*/ uq%3;#[0  
package NetFox; Nj_sU0Dt  
C<t>m_t9  
m#$za7  
public class Utility { }?J5!X  
RM1uYFs<  
CD1=2  
public Utility() _0["J:s9  
{ /A.i5=k  
/&:9VMMj  
j2 ^T:q[  
} l&Ghs@>Kl  
dO;vcgvb  
//线程睡眠 xg^^@o  
public static void sleep(int nSecond) @%nUfG7TQ  
{ xJLO\B+gM  
try{ TY\"@(Q|G  
Thread.sleep(nSecond); 25n (&NV  
} 'F?Znd2L  
catch(Exception e) !s*''v*  
{ 0r ; nz]'  
e.printStackTrace (); Ww&- `.  
} VQ<i$ I  
} TDE1z>h+"  
X&?lDL7?  
//日志 _ 1> 4Q%  
public static void log(String sMsg) {U '&9_y  
{ ENWB|@B  
System.err.println(sMsg); wV&f|JO0+  
} doO Ap9%  
<lmJa#  
y6Epi|8  
public static void log(int sMsg) {dx /p-Tv  
{ 0o$HC86w  
System.err.println(sMsg); wv.Ul rpx.  
} s]vJUC,s  
} 6a?$=y  
`ab\i`g9  
([CnYv  
/* x<j"DS}S)D  
**TestMethod.java ?U/Wio$@  
*/ |id79qY7g  
package NetFox; XQJ^)d00h  
u%1k  
8C,utjy  
public class TestMethod { if[o?6U4t  
4_762Gu%  
@Du}   
public TestMethod() Y `7#[g  
{ ///xx/weblogic60b2_win.exe #!Cter2  
try{ #G  +  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -Bo~"q  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hRa(<ZK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Eh@T W%9*  
fileFetch.start(); + lB+|yJ+  
} Mev-M2A  
catch(Exception e){e.printStackTrace ();} zt[4_;2Y  
+:]Aqyc\  
EPe]-C`  
} NVc! g  
-)O kG#J@  
B.mbKntK)R  
public static void main(String[] args) aDl, K;GL  
{ *Qg5Z   
new TestMethod(); ZE8/ m")  
} &[ u6oAR  
} X`3vSCn  
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3+5=?,请输入中文答案:八 正确答案:八