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)); akT6^cP^
} c(%|: P^
for(int i=0;i<nEndPos.length-1;i++) oE~Bq/p
{ .~}1+\~5
nEndPos = nStartPos[i+1]; 'RRE|L,
} }75e:w[
nEndPos[nEndPos.length-1] = nFileLength; yEoV[K8k
} JCaOK2XT;
} W%)Y#C
C-[1iW'
tl].r|yl
//启动子线程 ;>YzEo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $g7<Y*t[
for(int i=0;i<nStartPos.length;i++) !a<ng&H^U
{ +MLVbK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gNhQD*+>{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *#Wdc O`-
nStartPos,nEndPos,i); LDD|(KLR*.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UDni]P!E
fileSplitterFetch.start(); l+R+&b^
} yWya&|D9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q&V;(L62!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E!#WnSpnK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _y>~ yZx
nEndPos = " + nFileLength); PT9*)9<L
// fileSplitterFetch[nPos.length-1].start(); Faf&U%]*`
~nPtlrQa#*
7yba04D)
//等待子线程结束 Lxk[;j+
//int count = 0; rD>f|kA?L
//是否结束while循环 ZW}_Qs
boolean breakWhile = false; mQ=#nk$~g
L:8q8i
`g})|Gx
while(!bStop) 39|MX21k
{ rt|7h>RQ
write_nPos(); 'eX '
Utility.sleep(500); H4JTGt1"
breakWhile = true; l (%1jC8
JLJ;TM'4=
"Yca%:
for(int i=0;i<nStartPos.length;i++) N"1B/u
{ +@:x!q|^
if(!fileSplitterFetch.bDownOver) ym6K!i]q4
{ _,d~}_$`i
breakWhile = false; @fV9 S"TcM
break; 69 o7EA
} <rmvcim{*
} lA-h`rl/
if(breakWhile) l0hlM#
break; xjUtl
N&V`K0FU
g>9kXP+
//count++; e*n@j
//if(count>4) xp9pl[l
// siteStop(); yH}s<@y;7
} LraWcO\or'
N"y)Oca{
_{Hj^}+$
System.err.println("文件下载结束！"); *~H Sy8s
} Y)a^(!<H<
catch(Exception e){e.printStackTrace ();} evJ.<{M
} pXK^Y'2C!
Yir [!{
0{[,E.
//获得文件长度 TNr :pE<
public long getFileSize() BV+ Bk+
{ S/I/-Bp~
int nFileLength = -1; (2 a`XwR
try{ :Xd<74Nu
URL url = new URL(siteInfoBean.getSSiteURL()); .y,0[i V N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~| 6[j<ziL
httpConnection.setRequestProperty("User-Agent","NetFox"); K}U-w:{
>6pf$0
Zoc0!84<z
int responseCode=httpConnection.getResponseCode(); EUgs6[w 4
if(responseCode>=400) !7&5` q7
{ ,-e{(L
processErrorCode(responseCode); .K<Q&
return -2; //-2 represent access is error ED& `_h7?
} :<#nTh_@\'
B !=F2
uc"P3,M
String sHeader; XEZF{lP
.@Dxp]/B}
wuJ4kW$
for(int i=1;;i++) ;{o|9x|
{ 7 ^mL_SMj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FtC^5{V+V
//Utility.log(in.readLine()); r{%qf;
sHeader=httpConnection.getHeaderFieldKey(i); g2/8~cn8z
if(sHeader!=null) {T Ug.%u
{ R+,u^;\
if(sHeader.equals("Content-Length")) KFkoS0M5|
{ XNu^`Ha
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :TC@tM~Oy
break; NL0n009"c$
} q=qcm`ce
} Mzw X>3x
else H?y,ie#u
break; ?#YE`]
} CoAvSw
} {Fe[:\
catch(IOException e){e.printStackTrace ();} -{vKus
catch(Exception e){e.printStackTrace ();} +V^;.P</
M|(Q0 _8
td3D=Y
Utility.log(nFileLength); VEw"
_aMPa+D=P
Yr=Y@~ XL
return nFileLength; 6;qy#\}2
} r s?R:+
Ktm4 A O
0|\$Vp
//保存下载信息（文件指针位置） Uwx E<=z
private void write_nPos() Y0K[Sm>
{ ?vHU#
try{ :+|Z@KB
output = new DataOutputStream(new FileOutputStream(tmpFile)); X<; f
output.writeInt(nStartPos.length); Jl9k``r*
for(int i=0;i<nStartPos.length;i++) fku<,SV$O4
{ 1"M]3Kl
// output.writeLong(nPos); j;iAD:nf
output.writeLong(fileSplitterFetch.nStartPos); M*HnM(
output.writeLong(fileSplitterFetch.nEndPos); f\>M'{cV
} pDCeQ6?
output.close(); KX7>^Bt&k
} 6,9>g0y'NG
catch(IOException e){e.printStackTrace ();} hJ#xB6
catch(Exception e){e.printStackTrace ();} D^3vr2
} e?lyH
FA3~|Zg
EJ:%}HhA
//读取保存的下载信息（文件指针位置） =j*$ |X3W
private void read_nPos() Eq\M;aDq
{ EeRX+BM,
try{ c[1oww
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V0XvJ
int nCount = input.readInt(); !*. -`$x
nStartPos = new long[nCount]; V2|aN<Sx<
nEndPos = new long[nCount]; [ $n_6
for(int i=0;i<nStartPos.length;i++) ?+a,m# Yx
{ !|S43i&p
nStartPos = input.readLong(); VsE9H]v
nEndPos = input.readLong(); sCb=5uI
} =k0_eX0
input.close(); %vhnl'
} Z//+Gw<'
catch(IOException e){e.printStackTrace ();} sAD}#Zw$
catch(Exception e){e.printStackTrace ();} )i^<r;_z
} vv+z'(l
QR0Q{}wbqU
w{@o^rs
private void processErrorCode(int nErrorCode) %k?U9pj^
{ hUMf"=q+
System.err.println("Error Code : " + nErrorCode); %pd,%pg
} :'l^kSP_*C
thM4vq
hPePB=
//停止文件下载 364`IC( a
public void siteStop() 9g"2^^wD
{ T7u%^xm
bStop = true; )MchsuF<
for(int i=0;i<nStartPos.length;i++) }n2M G
fileSplitterFetch.splitterStop(); ],a5)kV
TS9|a{j3!
Yqi4&~?db
} B1C-J/J
} d]6#m'U
//负责部分文件的抓取 #& Rw&
**FileSplitterFetch.java 5ZK@`jkE
*/ Vq?p|wy
package NetFox; ,+xB$e
c>RFdc:U
q):5JXql~
import java.io.*; 9-DZU,`P
import java.net.*; A.F738Zp{Z
:~T99^$zA
,\n&I(
public class FileSplitterFetch extends Thread { DBD%6o>]K
&NoS=(s,
D9 |n)f
String sURL; //File URL MET' (m
long nStartPos; //File Snippet Start Position [8,yF D_U
long nEndPos; //File Snippet End Position ^ ALly2
int nThreadID; //Thread's ID `a/%W4
boolean bDownOver = false; //Downing is over t@N=kV
boolean bStop = false; //Stop identical @u]rWVy;\[
FileAccessI fileAccessI = null; //File Access interface \$e)*9)
Xudg2t)+K
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZR]25Yy
{ iIa'2+
this.sURL = sURL; ve/<=IR Zo
this.nStartPos = nStart; _5# y06Q
this.nEndPos = nEnd; Oz`BEyb]{
nThreadID = id; e`TH91@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A?%H=>v$
} r)~ T@'y
Vq\`+&A
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public void run() s<_)$}
{ }O^zl#
while(nStartPos < nEndPos && !bStop) K]0:?h;%Ld
{ f[a}aZ9)
ahOMCZF|
ps%q9}J
try{ `t9?=h!
URL url = new URL(sURL); dEA6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @&:ar
httpConnection.setRequestProperty("User-Agent","NetFox"); X{'q24\F
String sProperty = "bytes="+nStartPos+"-"; PCM-i{6/
httpConnection.setRequestProperty("RANGE",sProperty); -~ Mb
Utility.log(sProperty); 5Z\#0":e
80/F7q'tn
.#Z%1U%P.
InputStream input = httpConnection.getInputStream(); #9xd[A: N
//logResponseHead(httpConnection); Rh{zH~oZ
7-T{a<g
A1#%`^W9
byte[] b = new byte[1024]; #+5pgD2C
int nRead; x`mN U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {{MRELipW
{ DRgTe&+
nStartPos += fileAccessI.write(b,0,nRead); ul2")HL];
//if(nThreadID == 1) CS-uNG6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ayD}r#7
} }mdAM6
,Bo>E:u
}J1tdko#
Utility.log("Thread " + nThreadID + " is over!"); .CU5}Tv-
bDownOver = true; mkF"
//nPos = fileAccessI.write (b,0,nRead); 5v}8org
} Vq;A>
catch(Exception e){e.printStackTrace ();} ?yR&/a
} &n?^$LTPY
} 9;Ox;;w
:Q_<Z@2Y{
M9@ri^x
//打印回应的头信息 TGe;HZ
public void logResponseHead(HttpURLConnection con) T{Uc:Z
{ *"n vX2iz
for(int i=1;;i++) okv1K
{ C{DvD'^
String header=con.getHeaderFieldKey(i); Dzs[GAQ]
if(header!=null) YY!6/5*/]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \y)
Utility.log(header+" : "+con.getHeaderField(header)); J@X'PG< 6B
else ";Rtiiu
break; $8[r9L!
} }S$@ Ez6
} UE ,t8j
x{c/$+Z[
<l9-;2L4
public void splitterStop() !\L/[:n
{ +g]yA3
bStop = true; .0O2Qqdg
} 3*)ig@e6
S"$m]
yH*6@P4:0=
} Zrr5csE
,|plWIl~
.?e\I`Kk^'
/* ,NVsn
**FileAccess.java e `,ds~
*//文件访问(定位，写) F^LZeF[#t
package NetFox; FMkzrs
import java.io.*; -3lb@ 6I6
P7MeX(Tay
V6#K2
public class FileAccessI implements Serializable{ S'B|>!z@
jR#~I@q^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _({A\}Q|
RandomAccessFile oSavedFile; mJ`A_0
long nPos; {aJJ`t
>Ll$p0W
@wC5 g 4E
public FileAccessI() throws IOException n>`as
{ /'DsB%7g
this("",0); YH_7=0EJ
} -!L"')
X'% ;B
Bk\Gj`"7
public FileAccessI(String sName,long nPos) throws IOException z,:a8LB#[
{ njnDW~Snb
oSavedFile = new RandomAccessFile(sName,"rw"); -7&Gi +]
this.nPos = nPos; D<X.\})Md
oSavedFile.seek(nPos); D"ehWLj
} Xy &uZ
NDAw{[.%
#\ n8M
public synchronized int write(byte[] b,int nStart,int nLen) 0#*#a13
{ ] 0m&(9
int n = -1; 3lq Mucr
try{ TkO[rAC
oSavedFile.write(b,nStart,nLen); -,{-bi
n = nLen; xOHgp=#D
} [mr9(m[F
catch(IOException e) m7GR[MR
{ u=/CRjot
e.printStackTrace (); pOkLb #
} A4?+T+#d
WJ9cZL
^3FE\V/=
return n; ;/*6U
} -TOIc%
[kgdv6E
?k|H3;\
} =.`qixN
%-AE]-/HI
t"YNgC ^
/* k` (jkbEZ
**SiteInfoBean.java 5`RiS]IO]
*/ [e4]"v`N
package NetFox; ? j 9|5*
~w;]c_{.b
d4 (/m_HMu
public class SiteInfoBean { z>06hBv(?Y
"AhTH.ZP
G>+1*\c
private String sSiteURL; //Site's URL NAzX". g
private String sFilePath; //Saved File's Path k') E/n
private String sFileName; //Saved File's Name FG!X"<he
private int nSplitter; //Count of Splited Downloading File fQ=MJ7l
}AvcoD/b
N9<Ujom
public SiteInfoBean() h}Wdh1.M3
{//nSplitter的缺省值为5 1uk0d`JL
//default value of nSplitter is 5 3o|I[!2.
this("","","",5); ,mL !(US
} o!r8{L
<JwX_\?ln
!;!~n`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b2b75}_A
{ +EM_TTf4
sSiteURL= sURL; Y05P'Q
sFilePath = sPath; }/,CbKi,+
sFileName = sName; on7I l
this.nSplitter = nSpiltter; oq_6L\ ~
OcSEo7W
Q!FLR>8
} #s%-INcR
?<yM7O,4
Lh-`OmO0>F
public String getSSiteURL() WmQ01v
{ )*d W=r/$V
return sSiteURL; sfVf@0g
} 5]1h8PW!Y
pBC<u
{A o,t+j
public void setSSiteURL(String value) 9lo[&^<
{ 'snYu!`z
sSiteURL = value; iYbX
} cubk]~VD
HOp-P8z
*X38{rj
public String getSFilePath() 2spg?]
{ =4 X]gW
return sFilePath; ^R$'eG 4L?
} fXQiNm[P
^-M^gYBR
._96*r=o
public void setSFilePath(String value) a/uo}[Y
{ 3?s ?XAh
sFilePath = value; Bfv.$u00p
} U^Tp6vN d
Pu>N_^ C
T/P7F\R
public String getSFileName() d'9:$!oz
{ 9><mp]E4
return sFileName; r CRgzC
} >uI$^y1D
2n`Lg4=
9%iFV N'
public void setSFileName(String value) d=]U_+
{ s Fgadz6O
sFileName = value; bxXiQa
} U~2`P
oT|m1aGE
Yp4c'Zk
public int getNSplitter() *V;3~x!
{ gK3Mms]}m
return nSplitter; - n6jG}01b
} ; W7Y2Md
s-VSH
fH8!YQG8$
public void setNSplitter(int nCount) &VWlt2-R0h
{ Ld|V^9h1;
nSplitter = nCount; ~L+]n0*
} ^Dx#7bsDZR
} kYxS~Kd<
&}`K^5K|O:
W%!@QY;E(
/* y02u?wJ
**Utility.java XvSIWs
*/ }+Vv0jX|V
package NetFox; 8Vt4HD08
qSO*$1i
5QWNZJ&}d
public class Utility { ,dd WBwMK
aN^IP
lz~J"$b
public Utility() s([Wn)I
{ <2P7utdZ
)8{6+{5lu
(=T$_-Dj`}
} i!MwBYk
c/u_KJFF-n
//线程睡眠 Eb.;^=x
public static void sleep(int nSecond) ;~sr$6
{ y>(rZ^y&
try{ nb@"?<L!
Thread.sleep(nSecond); ?|t/mo|K?
} X$wehMBX
catch(Exception e) 9|!j4DS<
{ }&G]0hCT!
e.printStackTrace (); IvW@o1Q
} Z-|li}lDr
} iG[? ]]
Ds5NAp:x
//日志 ^@}#me@
public static void log(String sMsg) 9[|4[3K
{ (buw^ ,NwZ
System.err.println(sMsg); < `Z%O<X
} cINHH !v
H|+tC=]4IZ
5iWe-xQ>
public static void log(int sMsg) {:Vf0Mhb
{ =p\Xy*
System.err.println(sMsg); ,sb1"^Wc
} ~|) 9RUXr>
} ?TuI:dC
"]]q} O?
d]M[C[TOX
/* R^Bk]
**TestMethod.java } 21j
*/ .u< U:*
package NetFox; '>^Xqn
( D}"&2
|@`"F5@,
public class TestMethod { *:arva5
:z~!p~
w4:<fnOM
public TestMethod() \X@IkL$r
{ ///xx/weblogic60b2_win.exe 56s*A*z$ ;
try{ -fux2?8M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dokuyiN\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uh+jt,RB`
SiteFileFetch fileFetch = new SiteFileFetch(bean); zeTszT)
fileFetch.start(); 5L&:_iQZy
} AA7#c7
catch(Exception e){e.printStackTrace ();} aii'}c
BQ#jwu0e
<"I?jgo
} VC=6uB
`$9L^Yg,4
31 ]7z
public static void main(String[] args) b|E/LKa
{ uiK:*[
new TestMethod(); !Y%D 9
} >0T3'/k<H
} %vc'{`P
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