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)); u~\l~v^mj
} 3Ued>8Gv
for(int i=0;i<nEndPos.length-1;i++) `R@b`3*%v
{ 6o=Q;Mezl
nEndPos = nStartPos[i+1]; R,f"2 k
} dH_g:ocA
nEndPos[nEndPos.length-1] = nFileLength; -YJ4-]Z
} )L/o|%r!
} (^mpb
Rr"D)|Y;C(
29kR7[k
//启动子线程 5sI9GC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %mr6p}E|
for(int i=0;i<nStartPos.length;i++) .V.ga2+
{ <MzXTy3\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i[40p!~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6 TSC7jO
nStartPos,nEndPos,i); c!Wj^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <EM'|IR?
fileSplitterFetch.start(); (c|Ry[$|
} '-NHu +
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d8%sGH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WR5W0!'Tf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5KRI}f
nEndPos = " + nFileLength); x A"V!8C
// fileSplitterFetch[nPos.length-1].start(); WeE1 \
S?e*<s9k
Q5>]f/LD
//等待子线程结束 7kq6VS;p
//int count = 0; rO7[{<97m
//是否结束while循环 cC7&]2X +f
boolean breakWhile = false; J8#3?Lp
Dx>~^ ^<
]5sU =\
while(!bStop) \Ws$@J-M
{ :,1kSM%r
write_nPos(); Mv7=ZAm
Utility.sleep(500); ,@r 0-gL
breakWhile = true; IfzZ\x .
H#FH'@J
A_}6J,*u
for(int i=0;i<nStartPos.length;i++) E0aJ~A(Hv
{ ,<O|Iis
if(!fileSplitterFetch.bDownOver) L2{b~`UvP
{ J[jzkzSu`
breakWhile = false; K\y W{y1
break; 6<m9guv
} |P(8T'
} )bR`uV9<
if(breakWhile) Yrmd hSY
break; S/)yi
Ys+NIV#Q
A? T25<}
//count++; 3"p'WZ>
//if(count>4) NNn sq@?6
// siteStop(); *rv7#!].
} #55_hY#
!G~`5?CvE
EVW\Z 2N.
System.err.println("文件下载结束！"); *TC#|5
} 6![}Jvu>
catch(Exception e){e.printStackTrace ();} E4qQ
} e(Y5OTus
Uo=_=.GQ
rYPj3!#
//获得文件长度 xY<*:&
public long getFileSize() `IH*~d]
{ {I]>!V0j!
int nFileLength = -1; p%ZAVd*|#V
try{ NXSjN~aG2
URL url = new URL(siteInfoBean.getSSiteURL()); v9XevLs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /f]'_t0\.
httpConnection.setRequestProperty("User-Agent","NetFox"); ZfnJ&H'
;(Kj-,>
l?:S)[:
int responseCode=httpConnection.getResponseCode(); lnv&fu`1P
if(responseCode>=400) &*9' 0
{ Z:.*fs5
processErrorCode(responseCode); h_\OtoRa
return -2; //-2 represent access is error *IIuGtS
} `{ ` W-C
.F/0:)
)| 0(#R
String sHeader; zCI.^^<?
kWbD?i-
O[W/=j[
for(int i=1;;i++) O1Nya\^g<I
{ lc\%7-%:5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LjPpnjU
//Utility.log(in.readLine()); w<Ot0&&
sHeader=httpConnection.getHeaderFieldKey(i); rH9[x8e
if(sHeader!=null) k]~|!`
{ g4}K6)@
if(sHeader.equals("Content-Length")) F`M`c%
{ g^[BnP)I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v?s%qb=T
break; npMPjknl
} x/uC)xm
} *nlDN4Y[
else }T&~DVM
break; 2!?=I'uMA
} 1R"Z+tNB
} y)mtSA8
catch(IOException e){e.printStackTrace ();} $Qcr8~+a
catch(Exception e){e.printStackTrace ();} rnRWL4
lX/:e=
%OJq(}
Utility.log(nFileLength); !+_X q$9_
F5%IsAH
%:yVjb,Yf
return nFileLength; ^ wb9n
} `qhZZ{s)1U
Pa-{bhllu)
S3gd'Bahq
//保存下载信息（文件指针位置） 2-beq<I
private void write_nPos() `c?8i
{ X1o=rT
try{ =O>E>Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ti$_V_
output.writeInt(nStartPos.length); nTCwLnX(O
for(int i=0;i<nStartPos.length;i++) kerBy\^
{ %a|m[6+O
// output.writeLong(nPos); Ue(\-b\)
output.writeLong(fileSplitterFetch.nStartPos); S3ZIC\2
output.writeLong(fileSplitterFetch.nEndPos); t)hi j&wzu
} l(d3N4iz
output.close(); VF:95F;@
} PGhYkj2
catch(IOException e){e.printStackTrace ();} `Hd~H
catch(Exception e){e.printStackTrace ();} U:uFrb,
} v)<|@TD)
WT jy"p*
1"~$(@oxG
//读取保存的下载信息（文件指针位置） S^A+Km3VB
private void read_nPos() .~fov8
{ yny1i9 y
try{ Bb.U4#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nx@,oC4
int nCount = input.readInt(); ?Lbn R~/J
nStartPos = new long[nCount]; <\oD4EE_
nEndPos = new long[nCount]; J }|6m9k!
for(int i=0;i<nStartPos.length;i++) eDY)i9"W
{ }X~"RQf9
nStartPos = input.readLong(); lQ#='Jqfp
nEndPos = input.readLong(); Zw_'u=r >
} S#nW )=
input.close(); v$#l]A_D
} Ch73=V
catch(IOException e){e.printStackTrace ();} mq+<2 S
catch(Exception e){e.printStackTrace ();} \{;3'<
} @k)[p+)E
$^`@lyr
._TN;tR~'
private void processErrorCode(int nErrorCode) \e~5Dx1
{ a;=IOQ
System.err.println("Error Code : " + nErrorCode); w#{S=^`}
} I-m Bj8^;
aole`PD,l
_kdt0Vr,L
//停止文件下载 l<:\w.Gl
public void siteStop() RKy!=#;17
{ qm< mw"]
bStop = true; C/MQY:X4
for(int i=0;i<nStartPos.length;i++) AA0\C_W0p
fileSplitterFetch.splitterStop(); #~[{*[B+
vrIWw?/z?
JC iB;!y
} ^9 ^DA!'
} t]E@AJOK
//负责部分文件的抓取 VcLzv{
**FileSplitterFetch.java +h8`8k'}-2
*/ jmF)iDvjuZ
package NetFox; p\DSFB
h}Lrpr2r
w9675D+
import java.io.*; DA>TT~L
import java.net.*; y7x*:xR[
r9n:[A&HE
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public class FileSplitterFetch extends Thread { +asO4'r
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7G%:ckg
String sURL; //File URL 1}~`g ED
long nStartPos; //File Snippet Start Position ijgm-1ECk3
long nEndPos; //File Snippet End Position \LM.>vJ
int nThreadID; //Thread's ID p3V?n[/}
boolean bDownOver = false; //Downing is over d;i@9+
boolean bStop = false; //Stop identical qWD(rq+9
FileAccessI fileAccessI = null; //File Access interface B`:l;<&jX
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I8Y #l'z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \-8aTF
{ WZ=$c]gG
this.sURL = sURL; 3~?m?vj|Y
this.nStartPos = nStart; *!ecb1U5
this.nEndPos = nEnd; 73JrK_h
nThreadID = id; tac\Ki?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a\}` f=T
} klnk{R.>|
8vQR'<,
A=wG};%_
public void run() u:H:N]
{ ZS[Ut
while(nStartPos < nEndPos && !bStop) HSVl$66
{ lIPz"
L%+mD$@u
Pbt7T Q
try{ dSe d6
URL url = new URL(sURL); Dt(xj}[tC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =|dHD
httpConnection.setRequestProperty("User-Agent","NetFox"); ij1YV2v
String sProperty = "bytes="+nStartPos+"-"; 5v^tPGg4
httpConnection.setRequestProperty("RANGE",sProperty); a'A<'(yv
Utility.log(sProperty); 45&Rl,2
3,n"d-
MG~bDM4
InputStream input = httpConnection.getInputStream(); v-wZHkdd1
//logResponseHead(httpConnection); Z\cD98B#
Ss_}@p ^
kK/XYC 0D
byte[] b = new byte[1024]; eD7qc1*G
int nRead; d{"@<0i?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <W+9h0c
{ u60RuP&
nStartPos += fileAccessI.write(b,0,nRead); XlnSh<e
//if(nThreadID == 1) wB&5q!{!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i[:cG
} }F"98s W
&x;n^W;#
20}w.V
Utility.log("Thread " + nThreadID + " is over!"); )j\_*SoH
bDownOver = true; J4@-?xj=\q
//nPos = fileAccessI.write (b,0,nRead); 1}Y3|QxF
} `?b'.Z_J
catch(Exception e){e.printStackTrace ();} M8/:PmR<
} +(y8q
} N9*:]a
XyiaRW
K$w;|UJc
//打印回应的头信息 R_\o`v5
public void logResponseHead(HttpURLConnection con) { {:Fs
{ 6P:fM Y
for(int i=1;;i++) sG)aw`_j
{ FBbaLqgVF{
String header=con.getHeaderFieldKey(i); uB#U( jl
if(header!=null) BC\W`K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pWq+`|l$
Utility.log(header+" : "+con.getHeaderField(header)); r-yUWIr S
else %V+"i_{m
break; T]nAz<l),
} #<Lv&-U<KT
} <XQwu*_\
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jU* D
public void splitterStop() j9l32<h7]
{ P+=m.
bStop = true; 1z-A3a/-
} kD?@nx>
3W]gn8
0{ ~2mggh
} l1KgPRmEP
'nBP%
_>rM[\|X
/* wc.=`Me
**FileAccess.java 9[;da
*//文件访问(定位，写) &1R#!|h1W
package NetFox; aKWxLe
import java.io.*; <oV[[wl
>TY;l3ew
x^EW'-a
public class FileAccessI implements Serializable{ G"OP`OMDc
+ima$a0Zyt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FO%pdLs,
RandomAccessFile oSavedFile; 'Grii,
long nPos; J-<_e??
C\~}ySQc.e
6h2keyod
public FileAccessI() throws IOException q?dd5JzZy,
{ ydo9 P5E
this("",0); [P =P8-5
} BQ)>}YHk
()bQmNqmO=
Qrg- xu=
public FileAccessI(String sName,long nPos) throws IOException -Dx3*ZhP
{ X%j`rQk`
oSavedFile = new RandomAccessFile(sName,"rw"); 4=/jh:h
this.nPos = nPos; ZTV)D
oSavedFile.seek(nPos); |Z{#DOT
} A|S)cr8z
T3@2e0u )
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public synchronized int write(byte[] b,int nStart,int nLen) #dL,d6a
{ t(6]j#5
int n = -1; E+qLj|IU
try{ R[j?\#
oSavedFile.write(b,nStart,nLen); A,~KrRd
n = nLen; 4 ZnQpKg
} 5X=1a*2']
catch(IOException e) ]vvA]e
{ I9qFXvqL
e.printStackTrace (); yRyXlZC
} F |BY]{
N6"sXwm
,v K%e>e&
return n; cZ|*Zpk
} 41<h|WA
T`":Q1n
F:T(-,
} BqX"La,
?Y3i-jY
4@3\Ihv
/* Dg.~"h5mT
**SiteInfoBean.java e'A_4;~@s
*/ r=0PW_r:
package NetFox; #o/;du
x\8g ICf
oSD=3DQ;
public class SiteInfoBean { (WC =om
6E-eD\?I&
P"^Yx8L#
private String sSiteURL; //Site's URL <q$Tk,
private String sFilePath; //Saved File's Path jH9PD8D\
private String sFileName; //Saved File's Name 2|lR@L sr
private int nSplitter; //Count of Splited Downloading File )/@KdEA:
X^N6s"2
nUpj+F#
public SiteInfoBean() nt$PA(Y
{//nSplitter的缺省值为5 f&4+-w.:V|
//default value of nSplitter is 5 jn|NrvrX
this("","","",5); aOGoJCt C
} 3WF]%P%
y,`n9[$K\
#~nXAs]Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @[9
{ gi,7X\`KQ
sSiteURL= sURL; -%MXt
sFilePath = sPath; A?#i{R
sFileName = sName; ]sb?lAxh{
this.nSplitter = nSpiltter; 0SYJ*7lPX
[;,E cw^
#Mn?Nn
} #~-Xt!I
pP":,8Q{
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public String getSSiteURL() 2[`n<R\
{ V[kJ;YLPN
return sSiteURL; bT2c&VPCE
} vw!7f|Pg ~
siCi+Y
lhYJectJa
public void setSSiteURL(String value) kR %,:
{ %/w-.?bX
sSiteURL = value; )yb~ kbe
} z_xy*Iif
Ur< (TM
{z_cczJ-
public String getSFilePath() ];Noe9o
{ 9D\E0YG X/
return sFilePath; ZrEou}z(*
} ]I,&Bme
cI8\d 4/py
2EpQ(G J
public void setSFilePath(String value) ]@z!r2[
{ jW8ad{
sFilePath = value; V)~b+D
} }rmr0Bh
A2\hmp@A@7
Zc_F"KJL
public String getSFileName() )fXw~
{ 2(GYk
return sFileName; 1VFCK&
} +sn0bi/rG
n%36a(] t
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public void setSFileName(String value) 0N!rIz
{ K{I"2c
sFileName = value; WP\kg\o
} B]yO
,ov$`v
bz nMD
public int getNSplitter() W7|nc,i0\
{ Z:h'kgG&
return nSplitter; 09vVCM;DY
} !U4YA1>>
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Dj=$Q44
public void setNSplitter(int nCount) "kcix!}&
{ u8?$W%eW
nSplitter = nCount; ux^rF
} 4s|qxCks
} (bI/s'?K
)Az0.}
L:&'z:,<
/* ;>ml@@Z
**Utility.java A?n5;mvq#
*/ 7R5ebMW V
package NetFox; DQu)?Rsk
,tZL"
jpYZ) So-
public class Utility { "+O/OKfR0
'e<8j
N6BOUU]
public Utility() s."N7F
{ _ j'm2BAO
{C]tS5$Z
-0`n(`2
} \goiW;b
nZYO}bv\
//线程睡眠 }vP(SF6
public static void sleep(int nSecond) H^o_B1
{ vY4}vHH2
try{ ~S~+'V,d
Thread.sleep(nSecond); a)S6Z
} <ir]bQT
catch(Exception e) op-\|<i
{ Vy/G-IASb
e.printStackTrace (); ^u90N>Dvq
} nRX'J5Q m<
} 4;32f`
/i_FA]Go
//日志 =_N$0
public static void log(String sMsg) ?c"iV
{ lOb(XH9
System.err.println(sMsg); 7&jq =
} D\J.6W
NTK9`#SA
`{IL.9M!f
public static void log(int sMsg) =?]S8cth
{ .n.N.e
System.err.println(sMsg); q!><:"#[G
} k MV1$
} (t@!0_5
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c%wztP;L
/* G|t0no\f
**TestMethod.java ]i1OssV~>
*/ }=gD,]2x8
package NetFox; QAl4w)F
muK.x7zyl
y= 8SD7P'
public class TestMethod { 0Q#}:
ZifDU@J$t
-I*vl
public TestMethod() ,j(E>g3
{ ///xx/weblogic60b2_win.exe Ck m:;q
try{ {7$jwk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v/vPU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ui1s]R
SiteFileFetch fileFetch = new SiteFileFetch(bean); d|W=_7z
fileFetch.start(); 33~8@]b
} *].qm g%
catch(Exception e){e.printStackTrace ();} QWt3KW8)
kPAg*
|v#D}E
} QaA?UzB
k`z]l;:
"|,KXv')
public static void main(String[] args) $i!r> .Jo
{ U ){4W0
new TestMethod(); [P}mDX
} DV>;sCMJ %
} =C|^C3HK
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