http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); a7Fc"s*
} n,E=eNc
for(int i=0;i<nEndPos.length-1;i++) />,Tq!i\4}
{ W$X@DXT=o
nEndPos = nStartPos[i+1]; FNyr0!t,
} D'! v9}
nEndPos[nEndPos.length-1] = nFileLength; S)h0@;q
} )GpH5N'EI
} J"&jR7-9
T1&^IO-F7$
8'Y7lOXS
//启动子线程 \~#$$Q-qtU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2W_p)8t>b
for(int i=0;i<nStartPos.length;i++) .<Lbv5m
{ 4CT _MAj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WE hDep:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /s\_"p
nStartPos,nEndPos,i); {B_pjs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W=9Zl(2C
fileSplitterFetch.start(); P})Iwk|Z
} yl=_ /'*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wLDWD,"K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;hsem,C h7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .|pyloL.
nEndPos = " + nFileLength); hLZ<h7:
// fileSplitterFetch[nPos.length-1].start(); *XCid_{(
hpqM fz1
6Wm`Vj(s
//等待子线程结束 yz CQ
//int count = 0; (|F}B
//是否结束while循环 >brf7h
boolean breakWhile = false; oBm^RHTZ
I\BcG(hlJ
:UyNa0$l:"
while(!bStop) $p)7k
{ [CBhipoc
write_nPos(); t#Q" ;e
Utility.sleep(500); fn1G^a=
breakWhile = true; XM+o e0:[
h|MTE~
$E_9AaX
for(int i=0;i<nStartPos.length;i++) 4rmSo^vK
{ Nf#8V|
if(!fileSplitterFetch.bDownOver) qNLG-m,n<
{ ;}tEU'&
breakWhile = false; rT2gX^Mj&
break; YSvZ7G(m>
} qm.30 2
} fVU9?^0/)9
if(breakWhile) 6evW O!
break; )]=1W
= }&@XRLJ
:%!}%fkxH
//count++; &?],uHB?d
//if(count>4) #SHmAB
// siteStop(); fjE
} 3 e19l!B
\WDL?(G<
]8}+%P,Q
System.err.println("文件下载结束！"); 8$|<`:~J
} e~#"#?
catch(Exception e){e.printStackTrace ();} %~V+wqu
} X`[P11`
2\$P&L a
$a.!X8sHB.
//获得文件长度 PY4RwN
public long getFileSize() fQ\nK H~
{ r((2.,\Z
int nFileLength = -1; ,&DK*LT8U
try{ "Ih>>|r
URL url = new URL(siteInfoBean.getSSiteURL()); NF}QQwG3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U{IY F{;@
httpConnection.setRequestProperty("User-Agent","NetFox"); +<G |Ru-
)yV|vn
lZY0A#
int responseCode=httpConnection.getResponseCode(); h\oAW?^
if(responseCode>=400) V~Zi #o
{ *4i)aj
processErrorCode(responseCode); x[mxp/ /P
return -2; //-2 represent access is error 7,i}M
} b7 pD#v
rjmKe*_1V
I)xB I~x
String sHeader; Mp*S+Plp
Ywj=6 +;
")/TbTVu
for(int i=1;;i++) Di[}y;
{ 56;(mbW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *%G$[=
//Utility.log(in.readLine()); Oz\mIVC#
sHeader=httpConnection.getHeaderFieldKey(i); O/X;(qYd
if(sHeader!=null) C~do*rnM^
{ j@kL`Q\&I
if(sHeader.equals("Content-Length")) }Pm>mQZ},
{ T ;Ga G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hK!Z~
break; HT]v S}s
} BrW1:2w >\
} "6T: &>
else N30w^W&
break; "[`.I*WNo
} _%HpB=
} XA cpLj]
catch(IOException e){e.printStackTrace ();} ~c e?xr|
catch(Exception e){e.printStackTrace ();} Hpo/CY/
)+^1QL
x+kP,v
Utility.log(nFileLength); so* lV
br!:g]Vh
|{#=#3X
return nFileLength; o8 A]vaa
} R3MbTg
-rU~
'Ii%/ Ob!
//保存下载信息（文件指针位置） X(D$eV
private void write_nPos() ]!>ThBMa
{ O|#N$a&_N
try{ E,Q>jH
output = new DataOutputStream(new FileOutputStream(tmpFile)); cz8%p;F:
output.writeInt(nStartPos.length); K^V*JH\G
for(int i=0;i<nStartPos.length;i++) E"ju<q/Q
{ V\ud4
// output.writeLong(nPos); \bt+46y@]
output.writeLong(fileSplitterFetch.nStartPos); H'Mc]zw_,
output.writeLong(fileSplitterFetch.nEndPos); _":yUa0D
} f%LzWXA
output.close(); V?g@pnN"
} -+1it
catch(IOException e){e.printStackTrace ();} s*R\!L
catch(Exception e){e.printStackTrace ();} M@a?j<7P,m
} B/IPG~aMEZ
lO/<xSjNd
yVThbL_YJ
//读取保存的下载信息（文件指针位置） K)2ZH@
private void read_nPos() <B]\&
{ ^}XKhn.S'
try{ o.tCw\M$g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Bp3%*va
int nCount = input.readInt(); W)"PYC4
nStartPos = new long[nCount]; ;!<WL@C~
nEndPos = new long[nCount]; im&E\`L7
for(int i=0;i<nStartPos.length;i++) 0NLoqq
{ 0\tk/<w2
nStartPos = input.readLong(); ; 6Wlu3I
nEndPos = input.readLong(); GyV3]Qqj
} .p%p_
input.close(); $|v_ pjUu]
} GS|sx
catch(IOException e){e.printStackTrace ();} &Z682b$
catch(Exception e){e.printStackTrace ();} IVYWda0m
} uLYz!E+E
.O[RE_j
iw6qNV:\Z
private void processErrorCode(int nErrorCode) u,0N[.&N
{ ?45kN=%*s
System.err.println("Error Code : " + nErrorCode); !dfc1UjB
} u49zc9
sDnHd9v<?t
8tWOVLquJ
//停止文件下载 ^(I4Do~}
public void siteStop() 03*` T
{ de{KfM`W;
bStop = true; )rv5QH`i
for(int i=0;i<nStartPos.length;i++) eR r.j
fileSplitterFetch.splitterStop(); @psyO]D=j%
f[3DKA
&?^S`V8R*
} EWPP&(u3
} V,bfD3S3
//负责部分文件的抓取 oxE'u<
**FileSplitterFetch.java l%*KBME
*/ SU OuayE
package NetFox; 2Yt#%bj7^
U'S}7gya
#%k!`?^fbK
import java.io.*; X l#P@60
import java.net.*; gK/mm\K@
e Ll+F%@
9Vz1*4Ln
public class FileSplitterFetch extends Thread { zVe@`gc
7 Xe|P1@)
T;jp2 #
String sURL; //File URL MZf$8R
long nStartPos; //File Snippet Start Position }^WQNdws56
long nEndPos; //File Snippet End Position yiGq?WA7
int nThreadID; //Thread's ID vJDK]p<}
boolean bDownOver = false; //Downing is over `;b@a<Wl
boolean bStop = false; //Stop identical Ed,`1+
FileAccessI fileAccessI = null; //File Access interface O{a<f7 W
N-|E^XIV
y0>asl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d_=@1JM>
{ cVJ"^wgBt
this.sURL = sURL; <jF]SN
this.nStartPos = nStart; }\}pSqW
this.nEndPos = nEnd; #+HLb
nThreadID = id; 9tsI1]1[m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C{!L +]/
} IRNL(9H
Qk<W(
B PTQm4TN
public void run() &Yi)|TU3'R
{ S!<YVQq
while(nStartPos < nEndPos && !bStop) ?>5[~rMn
{ m\`dLrPX4j
/ pzdX%7
Ov"]&e(I[
try{ F,Q\_H##x4
URL url = new URL(sURL); D].!u{##
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %eWzr
httpConnection.setRequestProperty("User-Agent","NetFox"); >_P7k5Y^
String sProperty = "bytes="+nStartPos+"-"; l T~RH0L
httpConnection.setRequestProperty("RANGE",sProperty); "OF4#a17
Utility.log(sProperty); %JM:4G|q
gRv5l3k
GZ0? C2\
InputStream input = httpConnection.getInputStream(); &Oc^LV$6
//logResponseHead(httpConnection); =r"8J5[f
z(2pl}
c7Sa|9*dR
byte[] b = new byte[1024]; kcKcIn{
int nRead; S9R(;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '?dO[iQ$:
{ >)*0lfxTZ
nStartPos += fileAccessI.write(b,0,nRead); M"s+k
//if(nThreadID == 1) K:L_y1!T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &[W53Lqa
} }Hy4^2B
]S+KH \2
QruclNW{Bv
Utility.log("Thread " + nThreadID + " is over!"); 9,cMb)=0
bDownOver = true; Y{I,ipU.
//nPos = fileAccessI.write (b,0,nRead); M{4U%lk
} ]Ei*I}
catch(Exception e){e.printStackTrace ();} Id^)WEK4
} tRVz4fk[G
} 3,^.
FjV)QP H
MG:eI?G/'
//打印回应的头信息 RMs+pN<5
public void logResponseHead(HttpURLConnection con) w`_"R6
{ {NUI8AL46A
for(int i=1;;i++) ~s2la~gu
{ ]XjL""EbC
String header=con.getHeaderFieldKey(i); E RjMe'q4
if(header!=null) ZtGtJV"H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >Vph_98|
Utility.log(header+" : "+con.getHeaderField(header)); vw6DHN)k
else Oh5aJ)"D
break; c&'5r OY~
} cvVv-L<[S`
} #CRd@k?
KnC:hus
>4&0j'z"
public void splitterStop() VQ8Q=!]
{ 0y`r.)G
bStop = true; uc Ph*M
} )x3p7t)#
?$.JgG%Z+g
Z '~Ie~
} R!rj:f!>
(*Z:ByA
.oqe0$I
/* e=`=7H4P
**FileAccess.java ^&KpvQNW_
*//文件访问(定位，写) H;MyT Vl
package NetFox; ?N=`}}Ky-
import java.io.*; dy]ZS<Hz8G
elz0t<V
,olP}
public class FileAccessI implements Serializable{ Y+{jG(rg.F
S]Ye`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :!wl/X ~
RandomAccessFile oSavedFile; $"ACg!=M
long nPos; QzxEkTc;
@H$Sv
%+oqAYm+s
public FileAccessI() throws IOException 7Q9| P?&:z
{ W5>emx'>
this("",0); 6+4SMf3
} aU*}.{<!
aSMoee@!
'Pxq>Os
public FileAccessI(String sName,long nPos) throws IOException h@dy}Id
{ i,wZNX
oSavedFile = new RandomAccessFile(sName,"rw"); ?JBA`,-
this.nPos = nPos; :eIQF7-
oSavedFile.seek(nPos); QCO,f
} Q/0oe())
T+oOlug
D!z'Y,.
public synchronized int write(byte[] b,int nStart,int nLen) f)mOeD*u|
{ _9'hmej
int n = -1; QH_Ds,oH=
try{ 5_1\{lP
oSavedFile.write(b,nStart,nLen); )iid9K<HB
n = nLen; +J#8wh
} GT\yjrCd
catch(IOException e) 0rvBjlFT
{ /vC!__K9:
e.printStackTrace (); \/b[V3<"
} !E|m'_x*
33&l.[A"!}
2@IL n+#
return n; *Ms&WYN-
} EwmNgmYq
p5% %k-
jGT|Xo>t
} Gpi_p
sVGQSJJ5
bZr,jLEf
/* #c":y5:
**SiteInfoBean.java Xvoz4'Gme
*/ A}}dc:$C
package NetFox; 8I Ip,#%v
o 0T1pGs'
hn\d{HP
public class SiteInfoBean { W;l0GxOxQ
(&v,3>3]
aGfp"NtL
private String sSiteURL; //Site's URL o';/$xrH
private String sFilePath; //Saved File's Path RWX!d54&
private String sFileName; //Saved File's Name \Rb:t}
private int nSplitter; //Count of Splited Downloading File z"mpwmv5
~<~ ~C#R
|)C*i
public SiteInfoBean() ~I9o*cq
{//nSplitter的缺省值为5 fms(_Q:R?
//default value of nSplitter is 5 T\(k=0RM
this("","","",5); qS"#jxc==+
} %n GjP^
t%J1(H
~MXhp5PI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8qaU[u&$
{ 3Pgokj
sSiteURL= sURL; 0 x' d^
sFilePath = sPath; 0FY-e~xr
sFileName = sName; KV$4}{
this.nSplitter = nSpiltter; Jp%5qBS^
;E[Q/ tr:w
ipl,{
} $45.*>,
zx,9x*g
f$n5$hJlQ
public String getSSiteURL() iRlpNsN
{ U*E)y7MY
return sSiteURL; SD{)Sq
} p!=O>b_f
<<E9MIn_
Bf]Bi~w<
public void setSSiteURL(String value) esQ$.L
{ ^Y+Lf]zz*
sSiteURL = value; x#N_h0[i
} %+Y wzL{
U%q6n"[ Cr
K1BBCe
public String getSFilePath() ^G(Ee+PN@
{ OXbShA&1
return sFilePath; Gyy4zK
} EwU)(UK
k.K#i /t
%D8.uGsh
public void setSFilePath(String value) 3+s$K(%I
{ pMy:h
sFilePath = value; "y&`,s5}
} 1^E5VG1[
{jmy:e2
3l41"5Fy&
public String getSFileName() VN`fZ5*d~
{ rQ_@q_B.
return sFileName; 8.8t$
} m&gB;g3:
4oueLT(zc
O!{YwE8x9
public void setSFileName(String value) g#^MO]pY
{ {7@*cBqN
sFileName = value; S\<i`q
} {GLGDEb
`&7tADFB
{?IbbT
public int getNSplitter() geqP.MR
{ .#$2,"8
return nSplitter; vr'cR2
} >h#w~@e::
w:QO@
htR.p7&Tn
public void setNSplitter(int nCount) y32$b,%Xi,
{ RK &>!^
nSplitter = nCount; BLO ]78
} "O<ETHd0
} o!KDeY
,>S7c
W_JO~P
/* wN4#j}C
**Utility.java BR@m*JGajz
*/ 6`@J=Q?
package NetFox; BDWbWA 6
u"*DI=pwb
YnU)f@b#
public class Utility { 9yC22C:
fM4B.45j
LrbD%2U$j5
public Utility() p\ ;|Z+0=
{ 8mKp PwG0
bC1G5`v_D
iP"sw0V8
} >VkBQM-%
0O>ClE~P
//线程睡眠 m\0_1 #(
public static void sleep(int nSecond) %8tE*3iUF
{ pOo016afmA
try{ C$1W+(
Thread.sleep(nSecond); SI+Uq(k
} :1>?:3,`
catch(Exception e) A!B.+p[G
{ @nY]S\if
e.printStackTrace (); '1gfXC
} }r5yAE
} ^D$|$=|DH
"U-jZ5o"
//日志 =,#--1R7g
public static void log(String sMsg) ^0OP&s;"
{ =x\`yxsG
System.err.println(sMsg); Xi98:0<=
} nm,LKS7
ujX;wGje
nOGTeKjEJ
public static void log(int sMsg) _V-KyK
{ + '_t)k^
System.err.println(sMsg); !B}9gT
} 6p)AQTh>
} w>&*-}XX
MVsFi]-
akzGJ3g
/* 4\Y5RfLB_
**TestMethod.java L>h8>JvQ
*/ nTEN&8Y>R
package NetFox; E=p+z"Ui
Y"GNJtsL"
n|~y >w4
public class TestMethod { `.W2t5Y
`x`[hJ?i
o[Jzx2A<
public TestMethod() ,|({[9jA
{ ///xx/weblogic60b2_win.exe kO}&Oi,?
try{ l?U=s7s0?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S%i^`_=Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZNX38<3h
SiteFileFetch fileFetch = new SiteFileFetch(bean); %M@K(Qu
fileFetch.start(); U%nkPIFm
} 9Ux(
catch(Exception e){e.printStackTrace ();} MYWkEv7
=1l6(pJ
,_Z(!| rW
} 8Y?M:^f~
?BnU0R_r]
{arqcILr
public static void main(String[] args) 147QB+cE
{ vjuFVJwL
new TestMethod(); p+h$]CH
} ;Y?MbD
} 'u7-Qetj
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