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)); Iz#4!E|<
} .(.<
for(int i=0;i<nEndPos.length-1;i++) !|i #g$
{ ;H.V-~:P)
nEndPos = nStartPos[i+1]; Owi/e
} ujSoWs
nEndPos[nEndPos.length-1] = nFileLength; n=C"pH#
} m,!SDCq
} i,a"5DR8
Iia.`"S
A;RV~!xx
//启动子线程 ^bfZd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z[d13G;
for(int i=0;i<nStartPos.length;i++) 'ScvteQ
{ A)>#n)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )%MC*Z:^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w:QO@
nStartPos,nEndPos,i); i2c|_B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^Y%_{
fileSplitterFetch.start(); |g)>6+?]W
} 9jqsEd-SW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @v2ko5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A$5M.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FA$32*v
nEndPos = " + nFileLength); rf:H$\yw
// fileSplitterFetch[nPos.length-1].start(); HOFxOBV
kDWEgnXK,v
7#%Pry
//等待子线程结束 LlO8]b!P-^
//int count = 0; @x+2b0 b
//是否结束while循环 j;Z?q%M{6
boolean breakWhile = false; T-6<qh
m 0vW<
0FI |7
while(!bStop) -|KZOea
{ PBCGC^0{
write_nPos(); ix4]^
Utility.sleep(500); SnQT1U%
breakWhile = true; ybE2N
YnU)f@b#
T!KwRxJ23
for(int i=0;i<nStartPos.length;i++) HdI)Z<Krp
{ 9%iQ~
if(!fileSplitterFetch.bDownOver) N\ !
{ /}m*|cG/
breakWhile = false; D\-\U E/
break; o#,^7ln
} yvoz 3_!
} 7\,9Gcv1
if(breakWhile) bC1G5`v_D
break; iI";m0Ny
Gw$5<%sB
~<n.5q%Z
//count++; )B0%"0?`8
//if(count>4) >!xyA;
// siteStop(); ~;#}aQYo
} mA+:)?e5~
()l3X.t,$
~BmA!BZV`
System.err.println("文件下载结束！"); Q}L?o
} yW=+6@A4
catch(Exception e){e.printStackTrace ();} C$1W+(
} ]>VG}e~b
>- \bLr
")STB8kQ
//获得文件长度 nwUz}em?O
public long getFileSize() q_h (D/g
{ Bso#+v5
int nFileLength = -1; A,cXN1V
try{ qGV_oa74
URL url = new URL(siteInfoBean.getSSiteURL()); V>`ANZ4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fds 11 /c7
httpConnection.setRequestProperty("User-Agent","NetFox"); =oq8SL?bJ*
lt&(S)
SULFAf<
int responseCode=httpConnection.getResponseCode(); daI_@kY"
if(responseCode>=400) P8,Ps+
{ 4>>=TJ!M
processErrorCode(responseCode); 2.Qz"YDh =
return -2; //-2 represent access is error ?zf3Fn2y
} zR^Gy"
i9DD)Y<
M>]A!W=
String sHeader; \MOwp@|y
j,+]tHC-
*c94'Tcl
for(int i=1;;i++) *kl :/#
{ $}gMJG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k_=yb^6[U
//Utility.log(in.readLine()); Ptv'.<-
sHeader=httpConnection.getHeaderFieldKey(i); T+F]hv'
if(sHeader!=null) Qw}1q!89
{ TB!I
if(sHeader.equals("Content-Length")) -$Hu$Y}>
{ wgS,U}/i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F#sm^%_2
break; SXm%X(JU
} RDp
} (O5Yd 6u
else *{DTxEy
break; W8^m-B&
} zl|z4j'Irc
} yijP
catch(IOException e){e.printStackTrace ();} ro{!X,_$,
catch(Exception e){e.printStackTrace ();} +1!iwmch>
Kf[d@L
rR> X<
Utility.log(nFileLength); S=(O6+U
o[Jzx2A<
Go)$LC0Mi
return nFileLength; ^es]jng`
} "%gsGtS
eyCZ[SC
h^yqrDyJ
//保存下载信息（文件指针位置） `GCoi ?n7
private void write_nPos() "tzu.V-
{ 9Rnypzds
try{ }aVZ\PDg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3 !@
output.writeInt(nStartPos.length); "d_wu#fO)
for(int i=0;i<nStartPos.length;i++) YNEwX$)M,B
{ JNfL jfE)<
// output.writeLong(nPos); ) CP
output.writeLong(fileSplitterFetch.nStartPos); cQU;PH]
output.writeLong(fileSplitterFetch.nEndPos); -Z"4W
} N]A# ecm
output.close(); (jM0YtrD
} [>O!~
catch(IOException e){e.printStackTrace ();} ?l0Qi
catch(Exception e){e.printStackTrace ();} YA4D?'
} *j%x
mH'~pR>t
8b2 =n
//读取保存的下载信息（文件指针位置） Q5+1'mzAB
private void read_nPos() hy5[ L`B
{ <1D|TrP
try{ ]%' AZ`8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qd[_W^QI
int nCount = input.readInt(); BNu >/zGpB
nStartPos = new long[nCount]; 0ns\:2)cEB
nEndPos = new long[nCount]; }Y~Dk]*
for(int i=0;i<nStartPos.length;i++) Lnr9*dm6q
{ Iux3f+H
nStartPos = input.readLong(); )(G9[DG
nEndPos = input.readLong(); HC%Hbc~S_Q
} .A2$C|a*
input.close(); =&WIa#!=
} Ttluh *
catch(IOException e){e.printStackTrace ();} 8D='N`cN+
catch(Exception e){e.printStackTrace ();} Jj"{C]
} {>f"&I<xw
1@F-t94I
ju"z
private void processErrorCode(int nErrorCode) uzy5rA==
{ 9P?0D
System.err.println("Error Code : " + nErrorCode); pM?;QG;jA
} 8QrpNSj4
3 jZMXEG)
k?+ 7%A]
//停止文件下载 l|P"^;*zq
public void siteStop() Yj/afn(Jt
{ 'NEl`v*<P
bStop = true; u^" I3u8$
for(int i=0;i<nStartPos.length;i++) \Z[1m[{
fileSplitterFetch.splitterStop(); pHV^Kv#
r;#"j%z
!6!)H8rX
} _fHC+lwN
} B/twak\
//负责部分文件的抓取 sdFHr4
**FileSplitterFetch.java `H+"7SO
*/ yqT!A
package NetFox; j/ 5
tn]nl!_@
U'fP
import java.io.*; {q-&!l|
import java.net.*; J2bvHxb Rd
j#l=%H
t#k]K]
public class FileSplitterFetch extends Thread { z*\_+u~u
7oE0;'
2}hJe+#v
String sURL; //File URL A3jxjQ
long nStartPos; //File Snippet Start Position Pe`(9&iT.
long nEndPos; //File Snippet End Position C8U3+ s
int nThreadID; //Thread's ID sg2;"E@
boolean bDownOver = false; //Downing is over i}-uK,^
boolean bStop = false; //Stop identical AI|vL4*Xd
FileAccessI fileAccessI = null; //File Access interface "4N&T#
1[%3kY-h
?:(y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =8AT[.Hh
{ &@0~]\,D7
this.sURL = sURL; n5:uG'L\
this.nStartPos = nStart; 5S~ H[>A"
this.nEndPos = nEnd; I652Fcj
nThreadID = id; ^/f~\#R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7EJ2 On
} PTQ#8(_,
Ds9)e&yYrb
`2lS@
public void run() n6/Ous
{ WyN ;lId
while(nStartPos < nEndPos && !bStop) 0dchOUj
{ Z(mUU]
\TV
Rs%`6et}\
try{ LgqQr6y"
URL url = new URL(sURL); hlzB cz*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]3KeAJ
httpConnection.setRequestProperty("User-Agent","NetFox"); }A)\bffH
String sProperty = "bytes="+nStartPos+"-"; 3BFOZV+
httpConnection.setRequestProperty("RANGE",sProperty); 9/ <3mF@E
Utility.log(sProperty); h0{X$&:
dSM\:/t
F.9}jd{
InputStream input = httpConnection.getInputStream(); hZ&KE78?
//logResponseHead(httpConnection); Pfd1[~,
FuhmLm'p
0=Z[6Q@:
byte[] b = new byte[1024]; YF%gs{
int nRead; >!963>DR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n;g'?z=hy
{ 5ZCu6A
nStartPos += fileAccessI.write(b,0,nRead); CIudtY(:
//if(nThreadID == 1) NR4+&d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8wU$kK
} p.DQ|?
>)>f~>
gq=t7b
Utility.log("Thread " + nThreadID + " is over!"); *1|7%*!8
bDownOver = true; ACszx\[K3
//nPos = fileAccessI.write (b,0,nRead); =pH2V^<<#
} VYk:c`E
catch(Exception e){e.printStackTrace ();} J9^NHU
} #Hw|P
} ':*H#}Br-#
i8]EIXbMX
gabfb#
//打印回应的头信息 8z=# 0+0
public void logResponseHead(HttpURLConnection con) tsXKhS;/w
{ + G@N
for(int i=1;;i++) zl0{lV
{ Ak'=l;
String header=con.getHeaderFieldKey(i); _imuyt".+
if(header!=null) {bj!]j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #<{v~sVp&
Utility.log(header+" : "+con.getHeaderField(header)); oPe|Gfv\G
else x#1Fi$.
break; c~ss^[qx|
} RD$:.
} %OQdUH4x
X9x`i
W06aj ~7Z
public void splitterStop() ?cU,%<r
{ |]\zlH"w
bStop = true; fY<#KM6X
} 7;>|9k
t7=D$ua
CPz<iU
} N J3;[qJ
gZ@+62
-/f$s1
/* ,\4]uZ<
**FileAccess.java 2 bc&sU)X
*//文件访问(定位，写) (0-Ol9[
package NetFox; (t&RFzE?G
import java.io.*; Q}BMvR 9w
VjQ&A#
<jh4P!\&j
public class FileAccessI implements Serializable{ ^<I(
qBEp |V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z.VKG1e}
RandomAccessFile oSavedFile; -Vn#Ab_C
long nPos; YT(N][V
t.P@Ba^
DbGS]k<$
public FileAccessI() throws IOException zWY988fX0
{ >kXscbRL7
this("",0); fU>l:BzJK
} Xa[k=qFo
_ *f>UW*,
cBxGGggB
public FileAccessI(String sName,long nPos) throws IOException \n<! ld
{ 3h7RQ:lUi
oSavedFile = new RandomAccessFile(sName,"rw"); Y'U1=w~E
this.nPos = nPos; jTa\I&s,A
oSavedFile.seek(nPos); "i0>>@NR'
} {&5lZ<nu8A
T$;S
__=53]jGE
public synchronized int write(byte[] b,int nStart,int nLen) Ht[$s40P
{ H4g8 1V=
int n = -1; ~P3b5 -
try{ o[Ffa#sE
oSavedFile.write(b,nStart,nLen); u)oAQ<w
n = nLen; ?eS;Yc
} 4=Th<,<
catch(IOException e) J"aw 1
{ $Q*R/MY
e.printStackTrace (); m23"xnRB
} $nt&'Xnv
^KhJBM/Z
r=Xo;d*TE
return n; 2uj .*
} qPDNDkjDD
|Y3w6!$
78l);/E{v
} HVa9b;
o`YBz~2
@2E52$zu
/* s#^0[ Rt
**SiteInfoBean.java !)bZ.1o
*/ ?lC>E[
package NetFox; d6n_Hpxw^
UFj H8jSBx
wV )\M]@
public class SiteInfoBean { 71{Q#%5U~
(OiV IH
"z9C@T
private String sSiteURL; //Site's URL 6{6hz8
private String sFilePath; //Saved File's Path 'V]C.`9c
private String sFileName; //Saved File's Name KElEGW
private int nSplitter; //Count of Splited Downloading File L-9fo-
]Thke 4
t4oD> =,92
public SiteInfoBean() rl}<&aPH
{//nSplitter的缺省值为5 x,C8):\t`B
//default value of nSplitter is 5 LK}g<!o(
this("","","",5); %`i*SF(gV
} 8\s#law
SJ]6_4=y*
P!79{8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (_ G>dP_
{ ,:mL\ZED
sSiteURL= sURL; `,}7LfY
sFilePath = sPath; ^BA I/WP
sFileName = sName; s4fO4.bnm
this.nSplitter = nSpiltter; RJD{l+
G2|jS@L#
r;{$x
} rt^~ I\V
BL&AZv/T
]W;6gmV
public String getSSiteURL() YYpC!)
{ sJLOz>
return sSiteURL; Erw1y,mF
} X):7#x@uy
1^|#QMT
xf&[QG+Ef
public void setSSiteURL(String value) d.?}>jl
{ Q/g!h}>(.
sSiteURL = value; m""+$
} lpXGsKH2
hJ(vDv%
<|l}@\iRX
public String getSFilePath() 'Q=;I
{ h/n(
return sFilePath; fG1iq<~
} # >k|^*\
X\`']\l
IL|Q-e}Ol
public void setSFilePath(String value) Lf(( zk:pt
{ 3RaW\cWzg
sFilePath = value; Z3JUYEAS
} J$}]p
eN<L)a:J_
6FzB-],
public String getSFileName() /<)Vd
{ kqCsEtm]
return sFileName; lWYp
} 7?yS>(VmT
0g[ %)C
/K|(O^nw
public void setSFileName(String value) @Fc:9a@
{ %>$<s<y
sFileName = value; U>lf-iI2B
} 2]vTedSOl
&IN%2c
|'z8>1
public int getNSplitter() jh/,G5RM9
{ @$jV"Y
return nSplitter; aqEZhMy
} 8;?4rrS
!hq2AY&H)
%_W4\
public void setNSplitter(int nCount) DURWE,W>
{ ynmjIQ
nSplitter = nCount; - ]wT
} p?f\/
} [uU!\xe
AY5iTbL1
Y5tyFi#w[
/* <kFLwF?PM'
**Utility.java [eD0L71[
*/ =|-=4.b+|
package NetFox; l^&#9d
B,\VLX
t}eyfflZ
public class Utility { %]Z4b;W[Y
'{AB{)1
.yy-jf/
public Utility() ?C[?dg{n
{ E4eXfu
14 & KE3`
@#4-4.6I<x
} 2yK">xYY@
]^C 8Oh<
//线程睡眠 ??"_o3
public static void sleep(int nSecond) YHEn{z7
{ i#V(oSx
try{ tq59w
Thread.sleep(nSecond); W+&5G(z~
} d AcSG
catch(Exception e) I5M\PK/
{ KzVi:Hm
e.printStackTrace (); E@ :9|5
} U=bx30brh%
} >SI'Q7k
M,fL(b;2
//日志 n.+'9Fj
public static void log(String sMsg) rk8pL[|
{ N; }$!sNIm
System.err.println(sMsg); ZwDL
} >IIq_6Z#
To*+Z3Wd
S[K5ofV
public static void log(int sMsg) /i"hViCrlG
{ &q>8D'
System.err.println(sMsg); e\C-a4[C8P
} dQ8RrD=$&
} U:TkO=/>:
{T-\BTh&Q
_uO$=4Sd
/* kumV|$Y?kA
**TestMethod.java fc+-/!v
*/ -LiGO#U
package NetFox; ]u5TvI,C
OV]xo8a;
|E >h*Y
public class TestMethod { Rv&"h_"t
'oIE:#b
hH`x*:Qja
public TestMethod() VwI
{ ///xx/weblogic60b2_win.exe {c*$i^T
try{ kD#n/RBgf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9;L4\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jOV6%
SiteFileFetch fileFetch = new SiteFileFetch(bean); G0 EXgq8
fileFetch.start(); 1)= H2n4)
} dCoP qKy
catch(Exception e){e.printStackTrace ();} :Tpf8
ytY\&m
Ln#o:"E
} Sl8+A+
BHY-fb@R]H
MZ"V\6T]
public static void main(String[] args) 6>)fNCe`
{ aA4RC0'
new TestMethod(); t5E$u(&+'B
} SPV+ O{
} PaSwfjOnqr
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