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http断点续传简单实现(java)

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/* %6eQ;Rp*  
**SiteFileFetch.java QdtGFY4f,  
*/ HyKv5S$  
package NetFox; [) S&PK  
import java.io.*; >hsvRX\_ `  
import java.net.*; 1K&l}/zUl  
|\k,qVQ  
g\ q*,1  
public class SiteFileFetch extends Thread { PG*:3![2  
5w#7B  
%MH!L2|  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^a{cK  
long[] nStartPos; //开始位置 LZF %bJv  
long[] nEndPos; //结束位置 vS'l@`Eg]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t`oH7)nut  
long nFileLength; //文件长度 q@0g KC&U  
boolean bFirst = true; //是否第一次取文件 (>a8h~Na  
boolean bStop = false; //停止标志 !bg2(2z  
File tmpFile; //文件下载的临时信息 \mGo k<b4  
DataOutputStream output; //输出到文件的输出流 .qAlPe L:  
$G}!eV 6  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) d:SLyFD$q  
public SiteFileFetch(SiteInfoBean bean) throws IOException D,sb {N  
{ k^C^.[?  
siteInfoBean = bean; "-afHXED  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (HD8Mm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); uXkc07 r'  
if(tmpFile.exists ()) .Mb<.R3  
{ 3tu:Vc.:M  
bFirst = false; 2SV}mK U  
read_nPos(); ilr'<5 rq  
} QK0-jYG^  
else lZ>j:/R8^&  
{ ngI3.v/R  
nStartPos = new long[bean.getNSplitter()]; rf=ndjrH  
nEndPos = new long[bean.getNSplitter()]; ZW)_dg9  
} -gK*&n~  
n1J;)VyR  
}$E341@  
=s5g9n+7  
} ;VW->i a6  
nC2e^=^  
$3c9iVK~_  
public void run() 9_ru*j\  
{ !)-)*T  
//获得文件长度 lNs;-`I~  
//分割文件 >pRC$'Usx  
//实例FileSplitterFetch K2 b\9}  
//启动FileSplitterFetch线程 = iXHu *g  
//等待子线程返回 kX)QHNzP  
try{ .mwB'Ll  
if(bFirst) _6!@>`u~  
{ &$L6*+`h#  
nFileLength = getFileSize(); -J' 0qN!  
if(nFileLength == -1) Zc|V7 +Yx  
{ Y7_2pGvZ  
System.err.println("File Length is not known!"); Z;M th#  
} %`)lCK)2  
else if(nFileLength == -2) Yx3ivjX.>  
{ -~=?g9fGm6  
System.err.println("File is not access!"); (T 8In  
} KbTd`AIL  
else unD.t  
{ |D1:~z  
for(int i=0;i<nStartPos.length;i++) 4];<` %  
{ ,d`6 {ll  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); YHQvx_0yP  
} KJ#SE|  
for(int i=0;i<nEndPos.length-1;i++) oGvk,mh"(  
{ e~P4>3  
nEndPos = nStartPos[i+1]; pgipT#_K  
} -|g9__|@  
nEndPos[nEndPos.length-1] = nFileLength; e]DuV)k&  
} Bj*\)lG<  
} qac8zt#2 C  
H9%[! RF  
cf+EQY  
//启动子线程 l?<DY$H 0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'dvi@Jx  
for(int i=0;i<nStartPos.length;i++) _MLbJ  
{ v9 *WM3  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L"Dos +  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )\RG NJMC  
nStartPos,nEndPos,i); M'|?* aNK  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !=bGU=^  
fileSplitterFetch.start(); ;}KT 3Q<^  
} XmAu n  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4l rKU^-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?d' vIpzO!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U+-R2w]#q_  
nEndPos = " + nFileLength); 7#+>1 "\  
// fileSplitterFetch[nPos.length-1].start(); qe2@bG%2+F  
/CXQ&nwY9=  
}Yargj_Gn  
//等待子线程结束 \]|(w*C  
//int count = 0; <i~=-Z(  
//是否结束while循环 !D|c2  
boolean breakWhile = false; *4OB 88$  
h$l`)AH^  
76(/(v.x  
while(!bStop) !x[].Urj  
{ f<y-{.VnN$  
write_nPos(); 6lob&+  
Utility.sleep(500); ?M B Od9  
breakWhile = true; q#PMQR"C  
1YScZ  
noZ!j>f{@l  
for(int i=0;i<nStartPos.length;i++) SQT]'  
{ l1%ubu  
if(!fileSplitterFetch.bDownOver) MGLcM&oR  
{ kca#ssN  
breakWhile = false; /*e6('9s  
break; ~?z u5,vb  
} 7* R %zJ  
} fLg :+Ue<B  
if(breakWhile) &fe67#0r)  
break; >XPR)&t  
? J/NYV  
G#YBfPmr  
//count++; oS^g "hQ`\  
//if(count>4) 6Z<|L^  
// siteStop(); q+2v9K@  
} js;k,`  
 N<~LgH  
6%Pvh- ~_  
System.err.println("文件下载结束!"); kgP6'`}E[  
} Y?AvcY.  
catch(Exception e){e.printStackTrace ();} $CDRIn50  
} nhy:5eSK  
t~%(Zu>S  
q}gM2Ia'vY  
//获得文件长度 ${{[g16X  
public long getFileSize() *r)dtI*  
{ I{i6e'.jP  
int nFileLength = -1; E<'V6T9bi  
try{ 5}TTf2&Xo#  
URL url = new URL(siteInfoBean.getSSiteURL()); 2 $Umqt  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3,0b<vfSv  
httpConnection.setRequestProperty("User-Agent","NetFox"); a7sX*5t{R  
^B$cfs@*  
M^{=&  
int responseCode=httpConnection.getResponseCode(); 89UR w9  
if(responseCode>=400) {~`{bnx^]7  
{ >02p,W6S>  
processErrorCode(responseCode); YBL.R;^v  
return -2; //-2 represent access is error |]eWO#vs  
} >{[  
y*!8[wASHq  
l p|`n  
String sHeader; _wUg+Xs]  
K0|:+s@u  
Ctbc!<@o  
for(int i=1;;i++) :A+}fB IN  
{ 3LZvlcLb  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mhI   
//Utility.log(in.readLine()); {7Hc00FM  
sHeader=httpConnection.getHeaderFieldKey(i); -s^)HR l  
if(sHeader!=null) d%:J-UtG"  
{ Y/T-2)D  
if(sHeader.equals("Content-Length")) @<koL  
{  \|C*b<  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T0N6k acl  
break; wW7#M  
} e4FR)d0x  
} aH\A  
else 3Xm> 3  
break; a5pXn v]A  
} ;Irn{O  
} @M6F?;  
catch(IOException e){e.printStackTrace ();} :qj7i(  
catch(Exception e){e.printStackTrace ();} h0")NBRV&  
pGr4b:N  
,I H~  
Utility.log(nFileLength); vCUbbQz  
7n*"9Ai(  
AWg'J  
return nFileLength; "A0y&^4B@  
} ,z#S=I  
0,B"p  
.:O($9^Ho  
//保存下载信息(文件指针位置) :r7!HG _  
private void write_nPos() !Y 9V1oVf"  
{ 7bQST0 ?  
try{ T1%}H3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); xT-`dS0u  
output.writeInt(nStartPos.length); ^O!;KIe{g  
for(int i=0;i<nStartPos.length;i++) TLq^5,qG  
{ 6?a z  
// output.writeLong(nPos); Zr(eH2}0D  
output.writeLong(fileSplitterFetch.nStartPos); eQ*zi9na  
output.writeLong(fileSplitterFetch.nEndPos); gHFQs](G.  
} rDGrq9  
output.close(); JAy-N bb\  
} v6ei47-  
catch(IOException e){e.printStackTrace ();} n<1*cL:8B  
catch(Exception e){e.printStackTrace ();} D^6Q`o  
} jp|*kBDq\  
4I#@xm8)  
h]/3doP  
//读取保存的下载信息(文件指针位置) gA gF$H .  
private void read_nPos() E=91k.  
{ \Nk578+AA  
try{ 3R)|DGql=1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )4N1EuD6  
int nCount = input.readInt(); 7g:Lj,Z4L  
nStartPos = new long[nCount]; -@@ O<M^  
nEndPos = new long[nCount]; IaK J W?  
for(int i=0;i<nStartPos.length;i++) s1tkiX{>  
{ dptfIBYc+  
nStartPos = input.readLong(); !x! 1H5"  
nEndPos = input.readLong(); bXA%|7*  
} K"ly\$F  
input.close(); @>&b&uj7T  
} /qFY $vj  
catch(IOException e){e.printStackTrace ();} = ?BhtW  
catch(Exception e){e.printStackTrace ();} E{}J-_oS45  
} ^Jw=5 ImG  
r;p@T8k  
o#WECs>  
private void processErrorCode(int nErrorCode) (M<l}pl)  
{ gf}*}8D  
System.err.println("Error Code : " + nErrorCode); ;@ G^eQ  
} egH,7f(yP  
Y#+Ws0wN  
S(/ ^_Y  
//停止文件下载 y}?PyPz  
public void siteStop() [("2=Uz;  
{ .m.Ga|;  
bStop = true; wc-v]$DW  
for(int i=0;i<nStartPos.length;i++) Ai)>ot  
fileSplitterFetch.splitterStop();  FjMKb  
%:j`%F;R  
9W, %[  
} j& ykce  
} h!Y##_&&4  
//负责部分文件的抓取 3i\Np =  
**FileSplitterFetch.java 9|Ylv:sR  
*/ |nm}E_  
package NetFox; 3Pp+>{2_?  
Wf-XH|j[  
\.>7w 1p  
import java.io.*; <"}t\pT]  
import java.net.*; iP@ FXJJ  
CugZ!>;^  
?9>wG7cps7  
public class FileSplitterFetch extends Thread { ]68 FGH  
`\'V]9wS  
PHJHW#sv  
String sURL; //File URL OUFy=5(%:  
long nStartPos; //File Snippet Start Position G6l C[eK  
long nEndPos; //File Snippet End Position F_I!qcEQ  
int nThreadID; //Thread's ID  \< dg  
boolean bDownOver = false; //Downing is over "zkQu  
boolean bStop = false; //Stop identical $zF%F.rln  
FileAccessI fileAccessI = null; //File Access interface l]j;0i  
EPR85[k  
Q [C26U  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $$EEhy  
{ |'I>Ojm  
this.sURL = sURL; KW3<5+w]c  
this.nStartPos = nStart; <L<^uFB  
this.nEndPos = nEnd; O#p_rfQ  
nThreadID = id; 9XKqsvdS  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5Ar gM%  
} PKC0Dt;F.  
VMe  
?\(qA+iP0  
public void run() _+ Sf+ta  
{ o^Lq8u;i*  
while(nStartPos < nEndPos && !bStop) E " >`  
{ oE6`]^^  
7WY~v2SDF  
1Kr$JIcd  
try{ z30 mk  
URL url = new URL(sURL); EUVD)+it  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :U/]*0b  
httpConnection.setRequestProperty("User-Agent","NetFox"); #Ma:Av/ )  
String sProperty = "bytes="+nStartPos+"-"; !0P:G#o-$  
httpConnection.setRequestProperty("RANGE",sProperty); sI h5cT  
Utility.log(sProperty); Ul6|LTY  
[zXC\)&!  
Gt _tL%  
InputStream input = httpConnection.getInputStream(); q'4P/2)va  
//logResponseHead(httpConnection); fD3'Ye<R  
^,F G 9  
z]-m<#1  
byte[] b = new byte[1024]; &328pOT4  
int nRead; "6U@e0ht  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <QC7HR  
{ uPapINj  
nStartPos += fileAccessI.write(b,0,nRead); &:u3-:$:9  
//if(nThreadID == 1) #I*{_|}=  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Kg yt  
} *SIYZE'  
Vh2uzG  
>B=s+ }/ME  
Utility.log("Thread " + nThreadID + " is over!"); 7l[ @c|e  
bDownOver = true; i$`o,m#  
//nPos = fileAccessI.write (b,0,nRead); 12?!Z  
} wa{!%qu5.R  
catch(Exception e){e.printStackTrace ();}  +a%D+  
} {MyI3mvA  
} 5k9 vYW5k  
%NJ0 Y(:9(  
G-|c%g!ejf  
//打印回应的头信息 *uf)t,%  
public void logResponseHead(HttpURLConnection con) >;R`Q9s7  
{ .MRN)p  
for(int i=1;;i++) 5f?GSHA}  
{ *W`7JL,  
String header=con.getHeaderFieldKey(i); uv8k ea .(  
if(header!=null) +P Dk>PdEt  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RAk"C!&^m  
Utility.log(header+" : "+con.getHeaderField(header)); H V-;? 5  
else I8% -ii  
break; WTM  
} eThFRU3 F  
} Nnr[@^M5  
_+nk3-yQw  
'+ZJf&Ox  
public void splitterStop() *s-s1v  
{ rx 74v!  
bStop = true; 'DNxc  
} IVZUB*wv)b  
<DPRQhNW]  
jkta]#O  
} 6<>1,wbq  
}{j@q~w>$  
Mis B&Ok`k  
/* i$$h6P#  
**FileAccess.java }9W[7V?  
*//文件访问(定位,写) Vdefgq@<  
package NetFox; hkm}oYW+  
import java.io.*; %&VI-7+K  
(n~fe-?}8  
XP0;Q;WF}  
public class FileAccessI implements Serializable{ 7l/lY-zO  
0Z]HH+Z;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T3<1{"&  
RandomAccessFile oSavedFile; CGlEc  
long nPos;  s!  
&A.0(s  
wIR"!C>LE  
public FileAccessI() throws IOException reArXmU<u  
{ hmOGteAf-  
this("",0); J Eo;Fx]  
} vnVT0)Lel  
Mzg P@tB  
"S6";G^I  
public FileAccessI(String sName,long nPos) throws IOException zLJmHb{(  
{ Zi7cp6~7  
oSavedFile = new RandomAccessFile(sName,"rw"); OIpT9  
this.nPos = nPos; \'[tfSB  
oSavedFile.seek(nPos); Ii5U) "  
} [7HBn  
1 I.P7_/  
~E y+  
public synchronized int write(byte[] b,int nStart,int nLen) FXn98UFY  
{ "4Q_F3?_`  
int n = -1; r-L& ee   
try{ L@=$0p41;  
oSavedFile.write(b,nStart,nLen); #Y3-P  
n = nLen; b=\chCRJJ  
} WQ8 "Jj?k6  
catch(IOException e) @x}^2FE  
{ *`wz  
e.printStackTrace (); nw+^@|4  
} C96*,.j~'  
p=A, yGDV  
7RBEEE`)  
return n; (3D&GY!/  
} Ab/JCZNn  
0gW{6BtPWm  
3h>L0  
} H~vrCi~t"  
%,z;W-#gnY  
4%8den,|  
/* ?E+f<jol  
**SiteInfoBean.java u kZK*Y9P  
*/ ]Q0bL  
package NetFox; %xG<hNw/  
nh5=0{va|L  
_izjvg  
public class SiteInfoBean { g] }!  
bHx@   
tJ6Q7 J;n  
private String sSiteURL; //Site's URL ~8mz.ZdY  
private String sFilePath; //Saved File's Path hgW1g#  
private String sFileName; //Saved File's Name `[#id@Z1  
private int nSplitter; //Count of Splited Downloading File ]1>R8  
TI l 'Z7  
4@Db $PHs  
public SiteInfoBean() ;L-)$Dy4  
{//nSplitter的缺省值为5 WwZ3hd  
//default value of nSplitter is 5 s$fX ;  
this("","","",5); Ai[@2AyU  
} K$qY^oyQFw  
Me? I8:/  
k[ D,du')  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jVN06,3z  
{ #|(>UM\  
sSiteURL= sURL; Z : xb8]y  
sFilePath = sPath; G'}N?8s1  
sFileName = sName; Pp8G2|bz  
this.nSplitter = nSpiltter; z_R^C%0k  
)D/ ,QWk  
w}OBp^V^  
} _4L6  
5fiWo^s}  
%bF157X5An  
public String getSSiteURL() ercXw7{  
{ LS9,:!$  
return sSiteURL; I}|a7,8   
} *VJISJC  
iEr?s-or  
ilJ`_QN  
public void setSSiteURL(String value) g~.#.S ds  
{ *<67h*|)  
sSiteURL = value; r5nHYV&7  
} gYrB@W; 2  
FNF`Z  
N* &T)a  
public String getSFilePath() \ HUDZ2 s  
{ wf]?:'}  
return sFilePath; ]4[%Sv6]G  
} 2#^g] o-N  
_z BfNz9D  
Q Kr/  
public void setSFilePath(String value) ^JMG'@x  
{ |,oLZC Na  
sFilePath = value; T!y 9v5  
} EwV$2AK  
H,GjPIG  
9d/- +j'  
public String getSFileName() \a|~#N3?  
{ lGR0-Gh2  
return sFileName; bsU$$;  
} $<2d|;7r  
2 G*uv+=  
aAGV\o{^  
public void setSFileName(String value) e<9 ^h)G  
{  I2i'  
sFileName = value; 7* Y*_cH5  
} 5rck]L'  
|36%B7H  
d;gs1]E50  
public int getNSplitter() gU|:Y&lFZg  
{ ~!5Qb{^  
return nSplitter; H9ES|ZJs  
} 579D  
\WC,iA%Y  
+CdUr~6  
public void setNSplitter(int nCount) e_|<tYx><  
{ 98 5h]KQ  
nSplitter = nCount; v.C  
} "PRHQW  
} 8M,o)oH  
~? aFc)  
A~nqSe  
/* sPW :[  
**Utility.java :P2!& W  
*/ <^5$))r  
package NetFox; NI,>$@{  
8[X"XThj  
9%NsW3|  
public class Utility { zo "L9&Hzo  
gvWgw7z  
/LWk>[Z;  
public Utility() +<p&V a#  
{ 6AY( /N8V  
L7(FD v,?  
e/+.^ '{  
} t(roj@!x_o  
+3zQ"lLD^  
//线程睡眠 [DeDU:  
public static void sleep(int nSecond) Ty{ SZU J  
{ Q) aZ0 Pt  
try{ ,|VLOY ^  
Thread.sleep(nSecond); PH8 88O  
} nZ'jjS[!  
catch(Exception e) Nk\ni>Du3  
{ H#YI7l2  
e.printStackTrace (); /"A=Yf  
} ai?J  
} 9RJ#zUK  
oVHe<zE.  
//日志 `G: 1  
public static void log(String sMsg) P#!g P3  
{ m5N,[^-  
System.err.println(sMsg); )ADI[+KW  
} _MIheCvV  
:'<;]~f  
s Y1@~v  
public static void log(int sMsg) fOSk > gK  
{ ]C"?xy  
System.err.println(sMsg); )ej1)RU"  
}  Hk4k  
} |H^v8^%>zm  
nxuH22:  
.K4)#oC  
/* T`]%$$1s  
**TestMethod.java _qf~ hhi  
*/ `0U\|I#  
package NetFox; nTGf   
F?a 63,r  
"pK<d~Wu  
public class TestMethod { 2Uf/'  
%?+Lkj&  
! a\v)R  
public TestMethod() zTMLE~w  
{ ///xx/weblogic60b2_win.exe &Lzd*}7  
try{ T'lycc4~a  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SOsz=bVx  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (m! kg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5 Slz ^@n  
fileFetch.start(); x5\Du63  
} a;; Es  
catch(Exception e){e.printStackTrace ();} M'R ] ''  
~QUNR?h  
Sw>>]UjU  
} rt*>)GI]b  
5o4KV?"  
b1'849i'y=  
public static void main(String[] args) `IBNBJy  
{ kUGFg{"  
new TestMethod(); GL9'dL|  
} d#d&CJAfr  
} lcpiCZ  
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