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)); a" H WGY
} IL_d:HF|1
for(int i=0;i<nEndPos.length-1;i++) <9sO
{ F]mgmYD%
nEndPos = nStartPos[i+1]; X w.p
} =YG _z^'
nEndPos[nEndPos.length-1] = nFileLength; `HuCT6O
} n8hRaNHl2
} ^2wLxXO6
R<x'l=,D(
.ZMW>U>
//启动子线程 G Xt4j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v=95_l
for(int i=0;i<nStartPos.length;i++) >E,U>@+
{ $F.kK%-*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ESoAzo,u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gKg-O
nStartPos,nEndPos,i); kw`WH)+F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Il`tNr
fileSplitterFetch.start(); }qjCTEs}
} !Oi~:Pp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NU(AEfF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yFhB>i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C[WCg9Av
nEndPos = " + nFileLength); V3mAvmx
// fileSplitterFetch[nPos.length-1].start(); u>pBB@
Yav2q3
1|8<H~&
//等待子线程结束 _8G>&K3T<
//int count = 0; TEsnNi 1
//是否结束while循环 DF{OnF
boolean breakWhile = false; +%\oO/4Fs
,%YBG1E[y
%PJhy2
while(!bStop) s/Xb^XjS1
{ 7<9L?F2
write_nPos(); [@fz1{*
Utility.sleep(500); _GqS&JHSf
breakWhile = true; V[a[i>,Z
0iEa[G3
amQz^^
for(int i=0;i<nStartPos.length;i++) 69#8Z+dw7
{ nT#JOmv
if(!fileSplitterFetch.bDownOver) N~ANjn/wL
{ }%n5nLU`
breakWhile = false; }jSj+*
break; Ml>( tec
} }%{MPqg
} nws"RcP+Z
if(breakWhile) F=)eLE{W
break; *@V*~^V"J[
ix Z)tNz
VF0dE
//count++; pJ,@Y>
//if(count>4) *Zd84wRSj
// siteStop(); /-0' Qa+*
} TOI4?D]
h7qBp300
DlE_W+F
System.err.println("文件下载结束！"); bdh(WJh%
} G%TL/Z40
catch(Exception e){e.printStackTrace ();} &d`^E6#
} wX1ig
o4=Yu7L
iz}sM>^
//获得文件长度 )WR_ ug
public long getFileSize() <8(?7QI
{ INMP"1
int nFileLength = -1; dYOF2si~%
try{ p*;Qz
URL url = new URL(siteInfoBean.getSSiteURL()); UCqs}U8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Z\2*1y6
httpConnection.setRequestProperty("User-Agent","NetFox"); p {%t q$}.
ACBQ3
:X .,
int responseCode=httpConnection.getResponseCode(); heD,&OX
if(responseCode>=400) T%CxvZ
{ V"d=.Hb>
processErrorCode(responseCode); .?#uxd~>
return -2; //-2 represent access is error Sw! j=`O
} =L0fZf
VTh$a_P>
`"y{;PCt_
String sHeader; +?N}Y{Y&
?J|4l[x
kC^.4n om
for(int i=1;;i++) j.c8}r&
{ MguL$W&l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IbdM9qo7
//Utility.log(in.readLine()); q9}2
sHeader=httpConnection.getHeaderFieldKey(i); B/YcSEY;
if(sHeader!=null) k0&lu B%
{ Q&+c.S
if(sHeader.equals("Content-Length")) ,hE/II`-d'
{ *)PG-$6X&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~'BUrX\
break; lIDl1Z@Z
} |>sv8/!
} $Qq_qTJu?G
else Tt6{WDscZ
break; .98.G4J>
} QAaF@Do
} ( Yi=v'd
catch(IOException e){e.printStackTrace ();} w#{l4{X|
catch(Exception e){e.printStackTrace ();} tBl#o ^
+L6" vkz
91;HiILgT
Utility.log(nFileLength); 5^|"_Q#:
6:RMU
!1-&Y'+
return nFileLength; Qk7J[4
} }vsO^4Sjc
.wri5
T:#S86m
//保存下载信息（文件指针位置） {h^c
private void write_nPos() D% @KRcp^b
{ |B|@GF?:
try{ C"9"{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3B"7VBK{
output.writeInt(nStartPos.length); #`58F.
for(int i=0;i<nStartPos.length;i++) U 1F-~{r
{ 5\?3$<1I
// output.writeLong(nPos); :tlE`BIp
output.writeLong(fileSplitterFetch.nStartPos); w7ZG oh(
output.writeLong(fileSplitterFetch.nEndPos); =f4<({9
} Ge~,[If+
output.close(); ~1d!hq?/q
} iha9!kf
catch(IOException e){e.printStackTrace ();} Ut':$l=
catch(Exception e){e.printStackTrace ();} wzxdVn 'S
} z1}1*F"
)DRkS,I
DOT=U _
//读取保存的下载信息（文件指针位置） ,$PFI(Whk
private void read_nPos() %2zas(b9j
{ edTMl;4
try{ 9IOGc}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ${@q?iol
int nCount = input.readInt(); 1M=
nStartPos = new long[nCount]; uNg'h/^NZ|
nEndPos = new long[nCount]; zw< 4G[u
for(int i=0;i<nStartPos.length;i++) G#'Q~N
{ 'hy?jQ'|e
nStartPos = input.readLong(); pIvfmIm
nEndPos = input.readLong(); psu OJ-
} "'~|}x1Uv
input.close(); 8Kk3_ y
} W?=$V>)
catch(IOException e){e.printStackTrace ();} [jy0@Q9
catch(Exception e){e.printStackTrace ();} /=q.tDH=I
} RP(a,D|
76$*1jB
D{Oq\*
private void processErrorCode(int nErrorCode) "*+\KPCU
{ k06xz#pL
System.err.println("Error Code : " + nErrorCode); \hrrPPD1z
} UKOFT6|
))p$vU3
rAM*\=
//停止文件下载 3;y_qwA
public void siteStop() LSSW.Oz2L
{ m$,cH>E
bStop = true; G5Je{N8W
for(int i=0;i<nStartPos.length;i++) amMjuyW
fileSplitterFetch.splitterStop(); (=`Z0)=
Sf=F cb
oHOW5
} ujiZM
} Ap%d<\,Z
//负责部分文件的抓取 KUF$h Er
**FileSplitterFetch.java *X~B-a|nJ
*/ _2]O^$L
package NetFox; |MR%{ZC^i
Ze#Jhn@
v#iFQVBq
import java.io.*; vc )9Re$
import java.net.*; m dC`W&r
.F4oo=
a#^_"GX
public class FileSplitterFetch extends Thread { oDz*~{BHg
>vHH
'BqrJfv
String sURL; //File URL u/_Gq[Q,u
long nStartPos; //File Snippet Start Position (L`l+t1
long nEndPos; //File Snippet End Position $[j-C9W
int nThreadID; //Thread's ID ZEL/Ndk
boolean bDownOver = false; //Downing is over C5>{Q:.`e'
boolean bStop = false; //Stop identical #!w:_T%
FileAccessI fileAccessI = null; //File Access interface *4-r`k|@>/
be&6kG
Sc%aJ1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tDEXm^B2Sv
{ 2_Pz^L
this.sURL = sURL; ?UxG/]",
this.nStartPos = nStart; 4Sg<r,G
this.nEndPos = nEnd; #:]vUQ
nThreadID = id; $/NGNkl[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v;K{|zUdB
} ]&&I|K_
5OPS&:
Lv
public void run() PXOrOK
{ -;sJ25(
while(nStartPos < nEndPos && !bStop) 3js)niT9u
{ `K$:r4/[
HT{F$27W
TvQWdX=
try{ TjKzBAX
URL url = new URL(sURL); $.ymby
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !JT<(I2
httpConnection.setRequestProperty("User-Agent","NetFox"); ;6DR.2}?>
String sProperty = "bytes="+nStartPos+"-"; D /,|pC
httpConnection.setRequestProperty("RANGE",sProperty); rE/}hHU
Utility.log(sProperty); WpZy](,
e7Yb=/F
F@>w&A~K
InputStream input = httpConnection.getInputStream(); Nb#H@zm
//logResponseHead(httpConnection); 1.hOE>A%
/AK*aRU^
j zxf"X-
byte[] b = new byte[1024]; @)aXNQY
int nRead; /V#MLPA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~@b9
{ <wIp$F.
nStartPos += fileAccessI.write(b,0,nRead); I T*fjUY&
//if(nThreadID == 1) OhA^UP01-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [i,5>YIk
} Up]VU9z
@oe3i
x]yHBc
Utility.log("Thread " + nThreadID + " is over!"); r?Ev.m
bDownOver = true; X}65\6
//nPos = fileAccessI.write (b,0,nRead); TzD:bKE&
} ~G|{qVO7A
catch(Exception e){e.printStackTrace ();} {GGO')p
} :ofE8]
} :Olj
3L 1lq .
'W<a54T?z
//打印回应的头信息 b&U5VA0=1
public void logResponseHead(HttpURLConnection con) ql%]$`IV6
{ kVB}r.NHP
for(int i=1;;i++) EkfGw/WDw
{ 2i4Dal
String header=con.getHeaderFieldKey(i); <.y^
if(header!=null) n@yd{Rc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ggxrj'r
Utility.log(header+" : "+con.getHeaderField(header)); EmBfiuX
else ;GSfN
break; {ra Esb-X
} W~W?<%@
} gZ79u
]R2Z-2
45!`g+)
public void splitterStop() \fQgiX
{ $fU/9jTa
bStop = true; 9X^-)G>
} hQW#a]]V:
#h5Hi9LKf
Jn^Wzn[q
} j:vD9sdQ
@Tj 6!v
EC\rh](d 1
/* 9g^./k\8%
**FileAccess.java 5]2!Bb6>
*//文件访问(定位，写) 802]M
package NetFox; |[n|=ORI'
import java.io.*; L>R!A3G1
Y9(i}uTi
Zqe[2()
public class FileAccessI implements Serializable{ 5xn0U5U
0"D?.E"$r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \FaB!7*~
RandomAccessFile oSavedFile; khO<Z^wi[
long nPos; 5x L,~"
@+Anv~B.
*dn-,Q%`
public FileAccessI() throws IOException ^/RM;`h0
{ \2VZkVO9
this("",0); =_~'G^`tu
} JeSkNs|vB
'5+, lRu
"9Fv!*<-W
public FileAccessI(String sName,long nPos) throws IOException F@*r%[S/
{ jzOMjz~:)
oSavedFile = new RandomAccessFile(sName,"rw"); (Gb{ckzs
this.nPos = nPos; ,;-cz-,
oSavedFile.seek(nPos); uC$4TnoQx.
} N`mC_)
[}g5Z=l
*{n,4d\..
public synchronized int write(byte[] b,int nStart,int nLen) '2B0D|r"a
{ 7}HA_@[
int n = -1; S>zKD
try{ a*ixs'MJ
oSavedFile.write(b,nStart,nLen); KQy\l+\gM
n = nLen; hFF&(t2{^
} '{_tDboY
catch(IOException e) bsS|!KT
{ JL*]9$o
e.printStackTrace (); K^p"Z$$
} 6Yi,%#
\>CBam8d
a\.?{/
return n; cyn]>1ZM
} f#JF5>o
ZXRN?b
uqH! eN5
} 1JY90l$ME
[+2^n7R
A=>6$L];'
/* .oOt(K+
**SiteInfoBean.java 6}ewBAq%
*/ +mel0ZStS
package NetFox; 5 BG&r*U
I(eR3d:
1;sAt;/W8
public class SiteInfoBean { ojI"<Q~g
T</gWW
+2enz!z#k
private String sSiteURL; //Site's URL w4/)r-Z4I
private String sFilePath; //Saved File's Path x{w?X.Nt
private String sFileName; //Saved File's Name DWO:
private int nSplitter; //Count of Splited Downloading File `o-<,
?~9X:~6\
=njj.<BO
public SiteInfoBean() biuo.OG]
{//nSplitter的缺省值为5 :Gk~FRA|
//default value of nSplitter is 5 {?_)m/\
this("","","",5); DO*C]
} u8\QhUk'G
H`..)zL|
?n~j2-[<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lJ2/xE]
{ !I P*
sSiteURL= sURL; :H k4i%hGk
sFilePath = sPath; m$j;FKz+|
sFileName = sName; UeTp,
this.nSplitter = nSpiltter; +OP'/
dXN&<Q,
WWzns[$f
} f4^_FK&
5,fzB~$TX(
k!rz8S"
public String getSSiteURL() cMKh+r
{ kKO]q#9sO
return sSiteURL; <T9m.:l
} <o`]wOrl
bm|8Jbsb&
RGOwm~a
public void setSSiteURL(String value) %ua5T9H Z
{ `84yGXLK
sSiteURL = value; J?DyTs3Z
} *Ux"3IXO
ywBo9|%T
w%na n=
public String getSFilePath() )]Rr:i9n
{ I>|?B(F
return sFilePath; +[qy HTcG
} ;trR'~
u{^Kyo#v
:a`m9s 4
public void setSFilePath(String value) ;B@l0)7(x
{ ^4i3#}
sFilePath = value; <ZEll[0L
} rZ7 Ihof
jeNEC&J
AG%aH=TKp
public String getSFileName() F*u;'K
{ YTA&G
return sFileName; jiDYPYx;I
} |M&/(0
3._fbAN%e
?U[AE -*
public void setSFileName(String value) ~I74'
{ /PlsF
sFileName = value; 75ob1h"
} ujedvw;sO
Qw+">
#(G&%I A|;
public int getNSplitter() Zl*!pQ
{ N:.bnF(
return nSplitter; h !1c(UR
} *bK@A2`
OX2\H
<R$|J|
public void setNSplitter(int nCount) WF7RMQ51j
{ mBF?+/l
nSplitter = nCount; 5;*C0m2%i
} %K4-V5f
} lAQ&PPQ
195(Kr<5$
n1|%xQBU@
/* Q2o:wXvj
**Utility.java Syb:i(Y
*/ <|@9]>z
package NetFox; pWqahrWh
*SZ<ori
ORO~(%-(e
public class Utility { ZJqmD
C*$/J\6xy
(~#9KA1A}
public Utility() ~H.;pJ{ 8
{ Ic*Q(X
:c>,=FUT
`^/Q"zH
} NTC,Vr\A
Z=xrjE
//线程睡眠 2WoB;=
public static void sleep(int nSecond) Wd7*sa3T
{ >HDK<1>
try{ 3f3?%9
Thread.sleep(nSecond); B0:O]Ax6.^
} {_Y\Y&#
catch(Exception e) t?s1@}G^
{ TS;MGi0`}
e.printStackTrace (); o]vdxkU]
} b(yY.L=K
} !@Ox%vK
+$%o#~
//日志 mVxS[Gq
public static void log(String sMsg) m4EkL
{ 09Fr1PL
System.err.println(sMsg); bV"0}|A~K
} -6?5|\
` p)#!
0P|WoCX
public static void log(int sMsg) /+rHy7(\
{ 6 R!0v8
System.err.println(sMsg); &0 @2JS/!
} \t}!Dr+yN
} 4 1Ru@
!nTq"d%(W
B"G;"X
/* +Ta7b)
**TestMethod.java P?>p+dM
*/ GSypdEBj+w
package NetFox; (`T:b1
o0AREZ+I
<jxTI%'f59
public class TestMethod { +YP,LDJ!v
BwbvZfV|
9]l7j\L
public TestMethod() 7Ij'!@no
{ ///xx/weblogic60b2_win.exe Ur_~yX]Mo
try{ oM J5;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d<xBI,g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sq*sbdE
SiteFileFetch fileFetch = new SiteFileFetch(bean); [$B
fileFetch.start(); HuG|BjP
} EyozhIV
catch(Exception e){e.printStackTrace ();} E:#VS~
nNf/$h#;O
[9X1;bO#f
} gzxLHPiw
ZfS-W&6Z
_ u/N#*D
public static void main(String[] args) >!?u8^C
{ D[ny%9 :
new TestMethod(); ;4%^4<+3
} K@6$|.bc
} jf@#&%AC9
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