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http断点续传简单实现(java)

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/* $Pv;>fHu  
**SiteFileFetch.java MDI[TNYG  
*/ CvDy;'{y1  
package NetFox; `3GC}u>}  
import java.io.*; aMI\gCB/  
import java.net.*; *E lR  
.b'hVOs{  
T"ors]eI  
public class SiteFileFetch extends Thread { Twi:BI`.  
:j2G0vHIl(  
zOO:`^ m  
SiteInfoBean siteInfoBean = null; //文件信息Bean ]"?+R+  
long[] nStartPos; //开始位置 $w!;~s  
long[] nEndPos; //结束位置 AT.WXP0$A  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N&ZIsaK,j  
long nFileLength; //文件长度 iF:`rIC  
boolean bFirst = true; //是否第一次取文件 BCN<l +u  
boolean bStop = false; //停止标志 QJ1_LJ4)a  
File tmpFile; //文件下载的临时信息 |_7nvck  
DataOutputStream output; //输出到文件的输出流 iX ;E"ov]  
qC<!!473?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $7 1(g$6#  
public SiteFileFetch(SiteInfoBean bean) throws IOException ^D` ARH  
{ QQ*yQ\  
siteInfoBean = bean; DY]\@<ez  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); KFxy,Z$-4  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); j n[%@zD}  
if(tmpFile.exists ()) O{WJi;l  
{ :$eg{IXC"  
bFirst = false; haj\Dm  
read_nPos(); /Hxz@=LC1  
} >(>Fx\z}  
else ;533;(d* o  
{ j(JUOief  
nStartPos = new long[bean.getNSplitter()]; ;yh}$)^9  
nEndPos = new long[bean.getNSplitter()]; PP{2{  
} ~xz3- a/  
7k beAJ+{  
ZLK@x.=  
XHq8p[F  
} GS1Vcav<  
Q 5R7se_  
+Fu=9j/,j  
public void run() Sw!/ I PO  
{ hN% h.;s  
//获得文件长度 bqB gq  
//分割文件 4E&= qC]S  
//实例FileSplitterFetch 9D 2B8t"a  
//启动FileSplitterFetch线程 %\xwu(|kN  
//等待子线程返回 !L5[s  
try{ c o}o$}  
if(bFirst) 4.@gV/U(|  
{ NUiNn 7C  
nFileLength = getFileSize(); N[G<&f9  
if(nFileLength == -1) 8p3pw=p  
{ cZn B 2T?  
System.err.println("File Length is not known!"); =l&A9 >\  
} $O|J8;"v  
else if(nFileLength == -2) Rx e sK  
{ 6.fahg?E  
System.err.println("File is not access!"); S(;3gQ77  
} `9%Q2Al  
else j\t"4=,n  
{ +/idq  
for(int i=0;i<nStartPos.length;i++) mRI W9V  
{ JvFU7`4@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); i,G )kt'H  
} hGc')  
for(int i=0;i<nEndPos.length-1;i++) {. r/tV5IH  
{ rw*#ta O  
nEndPos = nStartPos[i+1]; ;dq AmBG{8  
} &^-quzlZ  
nEndPos[nEndPos.length-1] = nFileLength; K>H_q@-?f  
} X2#;1 ku  
} Oh9jr"Gm=  
:hB 8hTw]p  
v&:R{  
//启动子线程 ,~@0IKIA Q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lqC a%V  
for(int i=0;i<nStartPos.length;i++) i2<dn)K[~-  
{ z` b. ~<P  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @C),-TM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 41swG  
nStartPos,nEndPos,i); J('p'SlI  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r{m"E^K,  
fileSplitterFetch.start(); 8e_ITqV%  
} wg?:jK  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V+A1O k )  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "Q*Z?6[Z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hM*T{|y  
nEndPos = " + nFileLength); L@rKG~{Xy  
// fileSplitterFetch[nPos.length-1].start(); #vN\]e  
)9@I7QG?  
gd9ZlHo'Id  
//等待子线程结束 pH&Q]u; O  
//int count = 0; kTQ`$V(>&  
//是否结束while循环 'ad|@Bh  
boolean breakWhile = false; Jt4T)c9  
c9e  }P  
h#bpog  
while(!bStop) 1a {~B#  
{ "yMr\jt~-  
write_nPos(); =U3,P%  
Utility.sleep(500); %v++AcE  
breakWhile = true; xBGSj[1`i  
fT.5@RR7^  
9.5hQZ  
for(int i=0;i<nStartPos.length;i++) Hl&]r'bK  
{ >iP>v`J  
if(!fileSplitterFetch.bDownOver) cm]D"GFLY  
{ ;FYiXK%  
breakWhile = false; _\ n'uW$  
break; k07JMS?  
} bA#E8dlC_  
} 1{+Ni{  
if(breakWhile) [.P~-6~  
break; &libC>a[  
3"'|Ql.H  
]3#_BL)M8p  
//count++; U[~BW[[@f  
//if(count>4) ~..h=  
// siteStop(); c4CBpi?}  
} 1N< )lZl)  
~AuvB4xe~  
k}-%NkQ 9O  
System.err.println("文件下载结束!"); D@H'8C\  
} Y=/3_[G   
catch(Exception e){e.printStackTrace ();} FK!9to>  
} NXDV3MH=  
R{.wAH(  
Ki-CJ y  
//获得文件长度 57+^T}/>  
public long getFileSize() ?,|_<'$4T  
{ $Vp&Vc8  
int nFileLength = -1; r2QC$V:0  
try{ <u44YvLBm  
URL url = new URL(siteInfoBean.getSSiteURL()); $i@5'[jA  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?|^1-5l3  
httpConnection.setRequestProperty("User-Agent","NetFox"); *n?6x!A  
;3'}(_n  
'dj}- Rs  
int responseCode=httpConnection.getResponseCode(); J.":oD  
if(responseCode>=400) Z.m.Uyz{7  
{ HkxFDU-K  
processErrorCode(responseCode); I_xJ[ALdm  
return -2; //-2 represent access is error y)U8\  
} ,=>O/!s  
`(.ue8T  
cZL"e  
String sHeader; _}Jz_RS2`  
f7OfN#I  
fx.FHhVu  
for(int i=1;;i++) UeE& 8{=d  
{ l) VMF44  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5n.4>yOY  
//Utility.log(in.readLine()); c#9 zw[y-L  
sHeader=httpConnection.getHeaderFieldKey(i); ^f!d8 V  
if(sHeader!=null) &nPv%P,e  
{ !0`ZK-nA6  
if(sHeader.equals("Content-Length")) 4$.UVW\  
{ ) !ZA.sx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -$WiB  
break; {b/60xl?  
} $if(`8  
} ~"Ek X  
else  wb4 4  
break; _a*Wk  
} hU G Iy(  
} ~2A<fL,-  
catch(IOException e){e.printStackTrace ();} }Sp MHR`  
catch(Exception e){e.printStackTrace ();} iO#H_&L.p  
"_'9KBd!  
!l6B_[!@  
Utility.log(nFileLength); 9L:v$4{LU  
;?inf`t  
f{ S)wE>;  
return nFileLength; 1t!Mg{&e[x  
} 2T?t[;-  
Jc9SHCJ  
\"Sqr(~_  
//保存下载信息(文件指针位置) ? dSrY  
private void write_nPos() 2%vwC]A  
{ ,O a)  
try{ oF V9t{~j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); /q='~t  
output.writeInt(nStartPos.length); .:RoD?px  
for(int i=0;i<nStartPos.length;i++) [Z Ea3/  
{ |hp_X>Uv'  
// output.writeLong(nPos); 0e vxRcrzz  
output.writeLong(fileSplitterFetch.nStartPos); ?WUE+(oH>  
output.writeLong(fileSplitterFetch.nEndPos); pJ_Z[}d)c  
} FG#E?G  
output.close(); 5+%BZ  
} P'ZWAxd  
catch(IOException e){e.printStackTrace ();} aKCCFHq t!  
catch(Exception e){e.printStackTrace ();} WlZ[9,:p1  
} Q1eiU Y6  
y L&n)   
[zf9UUc~  
//读取保存的下载信息(文件指针位置) f.+e  
private void read_nPos() FIU( 2  
{ |BYD]vK  
try{ {2Gp+&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {AIZ,  
int nCount = input.readInt(); ~sSB.g  
nStartPos = new long[nCount]; -ZihEyG?V  
nEndPos = new long[nCount]; :sT<<LtI-  
for(int i=0;i<nStartPos.length;i++) z eIBB  
{ UQW;!8J#R(  
nStartPos = input.readLong(); >y]YF3?  
nEndPos = input.readLong(); :X`J1E]Rjd  
} &2?kD{  
input.close(); zP=J5qOZ8  
} bk4%lYJ"  
catch(IOException e){e.printStackTrace ();} $8i t&/JP,  
catch(Exception e){e.printStackTrace ();} ]s, T` (&  
} O gHWmb  
d\Dxmb]o  
6oUT+^z#  
private void processErrorCode(int nErrorCode) ol`]6"Sc  
{ ^Gs!"Y  
System.err.println("Error Code : " + nErrorCode); _5 y)m5I  
} PrN?;Z.  
iQa Q"s  
2? !b!  
//停止文件下载 kFk+TXLDIt  
public void siteStop() O~aS&g/sf  
{ RNvtgZ}k{X  
bStop = true; de ](l687I  
for(int i=0;i<nStartPos.length;i++)  pd X9G  
fileSplitterFetch.splitterStop(); OZt'ovY  
t]vX9vv+D  
I/^Lr_\  
} ?'_iqg3  
}  m?B@VDZ  
//负责部分文件的抓取 ?+Qbr$]  
**FileSplitterFetch.java (x=NA )  
*/ K{|;'N-1  
package NetFox; Q_uv.\*z_  
o~GhV4vq  
C!Tl?>Tt  
import java.io.*; s_1]&0<  
import java.net.*; ^u Z%d  
o)-Qd3d%S  
hZzsZQ`  
public class FileSplitterFetch extends Thread { .2Rh_ful  
\-sD RW  
$~ItT1k_  
String sURL; //File URL !4z"a@$  
long nStartPos; //File Snippet Start Position Jge;/f!i  
long nEndPos; //File Snippet End Position 4L5Wa~5\  
int nThreadID; //Thread's ID 6'wP?=  
boolean bDownOver = false; //Downing is over m&ZdtB|  
boolean bStop = false; //Stop identical C8G['aQ  
FileAccessI fileAccessI = null; //File Access interface =~HX/]zF  
$rjv4e}7  
@[JQCQ#r  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D %5 0  
{ LQ{4r1,u]  
this.sURL = sURL; {ZfTUt)-P  
this.nStartPos = nStart; <w,aS;v6jp  
this.nEndPos = nEnd; c8}1-MKs_R  
nThreadID = id; vk#xCggK  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ObsW!g  
} p(x[zn+%Y  
'x6Mqv1W  
"ht2X w  
public void run() 1^$Io}o:S  
{ e94csTh=  
while(nStartPos < nEndPos && !bStop) fk",YtS*  
{ 7`WK1_rR\  
;2X1qw>  
xSLN  
try{ &2) mpY8xQ  
URL url = new URL(sURL); .eeM&n;c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 74Kl!A  
httpConnection.setRequestProperty("User-Agent","NetFox"); j4NS5  
String sProperty = "bytes="+nStartPos+"-"; PqP)<d '/  
httpConnection.setRequestProperty("RANGE",sProperty); myJsRb5  
Utility.log(sProperty); 7qh_URt@  
%l5J  
Y8CXin h  
InputStream input = httpConnection.getInputStream(); 2oq>tnYyV[  
//logResponseHead(httpConnection); {(aJrSE<z  
%OzxR9  
8"S0E(,mu  
byte[] b = new byte[1024]; Ajq<=y`NzV  
int nRead; )I5f`r=Ry  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a{)"KAP  
{ 9h9Y:i*Gh5  
nStartPos += fileAccessI.write(b,0,nRead); #~ >0Dr  
//if(nThreadID == 1) Y*7.3 +#  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kk/qd)nk  
} `#l_`j=r$  
WRo#ZVt9$  
fd)}I23Q'  
Utility.log("Thread " + nThreadID + " is over!"); l5@k8tnz  
bDownOver = true; (2a~gQGD  
//nPos = fileAccessI.write (b,0,nRead); ~w!<J-z)  
} X#Hs{J~@p  
catch(Exception e){e.printStackTrace ();} kszYbz"  
} Li7/pUq>}!  
} ixU1v~T  
-aec1+o  
46$5f?Z  
//打印回应的头信息 `Y'}\>.#  
public void logResponseHead(HttpURLConnection con) @s@r5uR9B  
{ UDxfS4yI  
for(int i=1;;i++) Pu}2%P)p  
{ `[`eg<xj  
String header=con.getHeaderFieldKey(i); Wk$%0xZ7  
if(header!=null) jI y'mGaG  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q4Cw{2r  
Utility.log(header+" : "+con.getHeaderField(header)); `VS/ Xyp  
else "\e9Y<  
break; T T29 LC@  
} %3~jg  
} _\u'~wWl  
X}S<MA`  
6rR}qV,+{  
public void splitterStop() "S6d ^  
{ 1 "4AS_Q  
bStop = true; [Si`pPvl  
} <ZCjQkka>r  
xe_c`%_  
%)]{*#N4  
} [dUW3}APV  
3ne=7Mj  
)kg^.tP  
/*   5)mn  
**FileAccess.java )2:d8J\  
*//文件访问(定位,写) 5 kQC  
package NetFox; 1vQ*Br  
import java.io.*; ZfIQ Fh>  
g9 g &]  
`@eQL[Z9x  
public class FileAccessI implements Serializable{ [x9eamJ,H  
V<(cW'zA/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M`S >Q2{  
RandomAccessFile oSavedFile; NO;+:0n  
long nPos; B 6|=kl2C  
bY]aADv\  
*n}{ )Ef  
public FileAccessI() throws IOException >a]{q^0  
{  X&(1DE  
this("",0); %m{h1UQQ +  
} WG1x:,-  
!WAbO(l  
lKwIlp  
public FileAccessI(String sName,long nPos) throws IOException 3M/kfy  
{ ])vM# f  
oSavedFile = new RandomAccessFile(sName,"rw"); z,$^|'pP  
this.nPos = nPos; Dy0RZF4_  
oSavedFile.seek(nPos); i?||R|>;"'  
} joYj`K  
dTS 7l02  
CSIW|R@   
public synchronized int write(byte[] b,int nStart,int nLen) JrS|Ib)6  
{ 4fQ<A <2/  
int n = -1; $Z$BF  
try{ Br;1kQ%eC  
oSavedFile.write(b,nStart,nLen); EtKy?]i  
n = nLen; M/>^_zG  
} KN_3]-+B  
catch(IOException e) MT}9T  
{ a$"3T  
e.printStackTrace (); s}X2*o`,  
} 05$CIS>!  
>'7Icx  
8,=,'gFO  
return n; <D!"<&N  
} !-p5j3A4L  
arET2(h  
r ",..{  
} eUQrn>`  
x7>' 1  
`Z0FQ( r_  
/* K#tT \  
**SiteInfoBean.java z'j4^Xz?%$  
*/ Qne@Vf kA  
package NetFox; bRfac/:}  
?7*.S Lt  
Qw}uB$S>  
public class SiteInfoBean { Y'mtMLfMc  
(gQP_Oa(  
Rcc9Tx(zvQ  
private String sSiteURL; //Site's URL xo a1='  
private String sFilePath; //Saved File's Path  l|j  
private String sFileName; //Saved File's Name /R!:ll2  
private int nSplitter; //Count of Splited Downloading File O,x[6P54P  
C[6} 8J|  
`zw XfY,%  
public SiteInfoBean() ))66_bech  
{//nSplitter的缺省值为5 QVJq%P  
//default value of nSplitter is 5 ,` 6O{Z~  
this("","","",5); 2Jo|]>nl}u  
} lK 5@qG#  
Qzt'ZK  
s'b 4Me  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y 3h`uLQ  
{ FC@h6 \+a  
sSiteURL= sURL; ?(0=+o(`  
sFilePath = sPath; qILb>#  
sFileName = sName;  k{d]  
this.nSplitter = nSpiltter; N:x--,2  
~G,_4}#"pM  
_wH>h$E  
} VkdGGY  
1-0tG+  
/W9(}Id6  
public String getSSiteURL() ' Dcj\=8  
{ >mJH@,F:  
return sSiteURL; y)vK=,"  
} /#jH #f[  
)0+6^[Tqq  
0Q?)?8_  
public void setSSiteURL(String value) FkE)~g  
{ KW-GVe%8f  
sSiteURL = value; /o OZ>B%1s  
} E@,m +  
N,W ?}  
o=J-Ju  
public String getSFilePath() z36wWdRa6  
{ d^MRu#]  
return sFilePath; 'b)qP|  
} _NefzZWUJ  
:aQ.:b(n  
mC2K &'[  
public void setSFilePath(String value) ~(nc<M[  
{ =' uePM")  
sFilePath = value; 7-:R{&3Lm:  
} .V4-  
(Zg'])  
0vX4v)-^u  
public String getSFileName() xt_:R~/[  
{ aD]! eP/)  
return sFileName; 0FSNIPx  
} "i#aII+T  
Jvc:)I1NE7  
 bTU[E  
public void setSFileName(String value) vAp<Muj(a  
{ <qg4Rz\c]  
sFileName = value; n,U?]mr  
} ZDg(D"  
KpA1Ac)T  
?4A/?Z]ub  
public int getNSplitter() &AN1xcx\  
{ B (Ps/  
return nSplitter; H2H`7 +I,  
} *Nm$b+  
Mg #yl\v  
I4W@t4bZ  
public void setNSplitter(int nCount) $=iw<B r  
{ _%q~K (::  
nSplitter = nCount; jp_|pC'  
} =Ox}WrU~  
} #x;,RPw5  
 />Q}0H g  
aaP_^m O  
/* NV7k@7_{B  
**Utility.java q3AqU?f  
*/ s1q8r!2\w  
package NetFox; c/Xg ARCO  
rtS' 90`  
7:,f|>  
public class Utility { s$).Z(6  
=:aJZ[UU<2  
w lH\w?  
public Utility() AHRJ7l;a  
{ ak7kb75o  
8l_M 0F ,  
')U~a  
} 2]1u0-M5L  
U.KQjBi  
//线程睡眠 V(_1q  
public static void sleep(int nSecond) B*N1)J\5  
{ y(o)} m*0  
try{ J91[w?,  
Thread.sleep(nSecond); ,Cb3R|L8  
} B2e"   
catch(Exception e) /TyGZ@S>m  
{ gs5(~YiT6  
e.printStackTrace (); ]I[~0PCSX  
} @(Y!$><Is  
} 6$6QAW0+f  
8 q@Z  
//日志 pZ& ,YX  
public static void log(String sMsg) <%HRs>4  
{ 4b:|>Z-  
System.err.println(sMsg); PVsKI<  
} 7 p{Pmq[  
7 !$[XD  
0V4B Q:v  
public static void log(int sMsg) n:,mo}?X  
{ &^r>Q`u  
System.err.println(sMsg); OvtE)u l@  
} z Fo11;*D  
} f<NR6],}  
f#= c=e-A  
G 5;6q  
/* ?@ F2Kv  
**TestMethod.java x;17}KV  
*/ q0iJy@?A  
package NetFox; maXg(Lu  
_dJ(h6%3  
5J10S  
public class TestMethod { Nob(D'vSr  
y3zP`^  
Ix5&B6L8  
public TestMethod() rW:krx9  
{ ///xx/weblogic60b2_win.exe );$99t  
try{ TaN{xpo  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rZ~w_DK*  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); flsejj$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )h8}{*  
fileFetch.start(); bC/":+s& p  
} KwuucY  
catch(Exception e){e.printStackTrace ();} Upe}9xf  
{_QdB;VwH  
1u 9hA~rj  
} p+ CUYo(  
iRzFA!wH  
<s9?9^!!V^  
public static void main(String[] args) =V[uXm  
{ ~SnUnNDm`  
new TestMethod(); Jsz!ro  
} Z!)~?<gcq:  
} n t}7|h|  
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