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)); }*s`R;B|,
} =WM^i86
for(int i=0;i<nEndPos.length-1;i++) Dg o-Os@
{ 2nkymEPu
nEndPos = nStartPos[i+1]; b.|k j
} 0Tq=nYZA
nEndPos[nEndPos.length-1] = nFileLength; :B 9>
} 25{-GaB
} 6tF_u D
qPF`=#
jiqE^j3;
//启动子线程 Dbl+izF3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _T\cJcWf
for(int i=0;i<nStartPos.length;i++) &hu>yH>j
{ ~EtwX YkRZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;7E c'nC4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yXT8:2M
nStartPos,nEndPos,i); R,dbq4xkl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f@Yo]FU
fileSplitterFetch.start(); 1s/548wu
} 1Y'NG<d_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "."ow|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B-UsMO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fj4>)!^kM
nEndPos = " + nFileLength); {2F@OfuCF
// fileSplitterFetch[nPos.length-1].start(); @8*lqV2
^:~!@$*;6
Hg5:>?Lw@
//等待子线程结束 @L$!hTaP
//int count = 0; d$hBgJe>N
//是否结束while循环 -}(2}~{e(
boolean breakWhile = false; Kv9Z.DY
H)+QkQb}
e2^TQv2(=e
while(!bStop) 1]69S(
{ s@IgaF {
write_nPos(); 4-m6e$p;
Utility.sleep(500); vb6kr?-i*
breakWhile = true; Qk72ra)
lhC hk7l
QQJf;p7
for(int i=0;i<nStartPos.length;i++) s }Ql9
{ R,ZG?/#uM9
if(!fileSplitterFetch.bDownOver) 6n^@Ps
{ LXqPNVp#
breakWhile = false; s'|t2`K("
break; ?4^ 0xGyE
} />6ECT
} 0SDnMij&bf
if(breakWhile) #a9O3C/MP
break; u'nQC*iJb
t)1`^W}
6?'7`p
//count++; ,u>[cRqw
//if(count>4) Ol~M BQs
// siteStop(); TJ1h[
} =*1NVi $n
h+ud[atk.
stUUez>
System.err.println("文件下载结束！"); Re&"Q8I.8
} SL-;h#-y 4
catch(Exception e){e.printStackTrace ();} C]p@7"l
} .G#li(NWH
A,BYi$
f,4erTBH
//获得文件长度 MqJ5|C.q
public long getFileSize() C!|LGzs0
{ "Kdn`zN{
int nFileLength = -1; }Ba_epM
try{ vd)zvI
URL url = new URL(siteInfoBean.getSSiteURL()); 8CZ%-}-%$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kRc+OsY9
httpConnection.setRequestProperty("User-Agent","NetFox"); Qz3Z_V4k9
le]~Cy0
> K?OsvX
int responseCode=httpConnection.getResponseCode(); Fn7OmxfD
if(responseCode>=400) MXa^g"
{ uZZRFioX|
processErrorCode(responseCode); pQKSPr
return -2; //-2 represent access is error a eeor
} -58q6yA
O`Gq7=X
1"L"LU'
String sHeader; r5Tdp)S
<l$ d>,
Z Cjw)To(
for(int i=1;;i++) a5GLbanF
{ yji[Yde;|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {eV8h}KIl
//Utility.log(in.readLine()); [IQ|c?DxpL
sHeader=httpConnection.getHeaderFieldKey(i); ? ep#s$i
if(sHeader!=null) ".tL+A[
{ }&t>j[
if(sHeader.equals("Content-Length")) p*&0d@'r
{ ,_fz)@)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4]uj+J
break; BUJ\[/
} P0jr>j@^-
} 9MYk5q.X:
else Cq"KKuf
break; ~?AEtl#&"
} <ZF|2
} Ch_rV+
catch(IOException e){e.printStackTrace ();} U8w_C\Q
catch(Exception e){e.printStackTrace ();} `daqzn
67YC;J]n=z
akxNT_
Utility.log(nFileLength); hd(FOKOP
AO$AT_s
lGl'A}]#$
return nFileLength; UtQey ;w
} <4"-tYa
M 9t7y
FM >ae-L-
//保存下载信息（文件指针位置） jdP)y]c
private void write_nPos() hTr5Q33y>
{ /Hyz]46
try{ CwA_jOp
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~ELMLwn.
output.writeInt(nStartPos.length); '7-Yo Q
for(int i=0;i<nStartPos.length;i++) ,vJt!}}
{ aa`(2%(:
// output.writeLong(nPos); jO-?t9^
output.writeLong(fileSplitterFetch.nStartPos); f'^uuO#x
output.writeLong(fileSplitterFetch.nEndPos); '4[=*!hs!
} G^~[|a4`
output.close(); ;Y$>WKsV
} 6Dlm.~G
catch(IOException e){e.printStackTrace ();} 0=j }`
catch(Exception e){e.printStackTrace ();} -n|bi cP
} xH-d<Ht,7
~&i4FuK
h[ DNhR
//读取保存的下载信息（文件指针位置） Y%s:oHt
private void read_nPos() \k.`xG?
{ E-bswUVaEE
try{ p,Ff,FfH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9-KhJq%
int nCount = input.readInt(); Oj5UG*
nStartPos = new long[nCount]; ~RhUg~o
nEndPos = new long[nCount]; 2bp@m;g$
for(int i=0;i<nStartPos.length;i++) <v_=k],W
{ 'o>)E>
nStartPos = input.readLong(); 4Gc M
nEndPos = input.readLong(); ,ks2&e
} MtLWpi u@[
input.close(); "|SMRc
} CLR1CGnn7
catch(IOException e){e.printStackTrace ();} zM9#1^X
catch(Exception e){e.printStackTrace ();} "O&93#8
} N:1aDr;
-8TJ:#|N
`g)}jo`W
private void processErrorCode(int nErrorCode) Mt[yY|Ec|
{ ToXWFX
System.err.println("Error Code : " + nErrorCode); 6>>; fy2
} ZZw`8 E
[{znwK@
"TV'}HH
//停止文件下载 )pB#7aEw
public void siteStop() o.+;]i}D
{ {f/qI`
bStop = true; PobX;Z
for(int i=0;i<nStartPos.length;i++) @T'^V0!-q:
fileSplitterFetch.splitterStop(); 1^~&"s U
g9_zkGc7
{keZ_2
} sZ.<:mu[
} DJP6Z
//负责部分文件的抓取 $*Ucfw1T
**FileSplitterFetch.java zTz}H*U
*/ ?bTfQH vX
package NetFox; [BWq9uE
rPV Q#iB
(`x_MTLL
import java.io.*; !NXjax\r
import java.net.*; aO6\e>
;Rrh$Ag
Y-VDi.]W
public class FileSplitterFetch extends Thread { =C"[o\]VV
iSW2I~PD
>p_W(u@ z$
String sURL; //File URL -t`kb*O3`
long nStartPos; //File Snippet Start Position o+A7hBM^
long nEndPos; //File Snippet End Position 8fC4j`!
int nThreadID; //Thread's ID H4$qM_N
boolean bDownOver = false; //Downing is over nL@'??I1
boolean bStop = false; //Stop identical xL}i9ozZ
FileAccessI fileAccessI = null; //File Access interface cc@W 6W
(lk9](;L
wi(Y=?=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #mxOwvJ
{ vygzL U^
this.sURL = sURL; d?,'$$aB
this.nStartPos = nStart; > p`,
this.nEndPos = nEnd; "<,lqIqA;
nThreadID = id; ~q$]iwwqT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y(Q 0m|3P
} q<3nAE$?=
Nx}nOm
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public void run() <Ap_#
{ `Os=cMR
while(nStartPos < nEndPos && !bStop) g4K+AK
{ r\NqY.U&
l:HQ@FX
1w,_D.1'
try{ p`tz*ewC
URL url = new URL(sURL); I _nQTWcm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |9*Rnm_
httpConnection.setRequestProperty("User-Agent","NetFox"); ,d"T2Hy
String sProperty = "bytes="+nStartPos+"-"; b<h((]Q>^
httpConnection.setRequestProperty("RANGE",sProperty); c_/BS n
Utility.log(sProperty); hkK>h
m=l>8
u 3WU0Z`
InputStream input = httpConnection.getInputStream(); |G j.E
//logResponseHead(httpConnection); .N(R~_
G%F#I
ysaRH3M
byte[] b = new byte[1024]; OC! {8MR
int nRead; ]_KWN$pd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _i=*0Q
{ * #yF`_p
nStartPos += fileAccessI.write(b,0,nRead); >6es 5}
//if(nThreadID == 1) *G"hjc$L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "4b{YWv
} `?VK(<w0q
hY)zKX_r
ZCCCuB
Utility.log("Thread " + nThreadID + " is over!"); CD1Ma8I8
bDownOver = true; -rDfDdT
//nPos = fileAccessI.write (b,0,nRead); CL<-3y*
} u`ir(JIj]
catch(Exception e){e.printStackTrace ();} 3.Fko<D4jD
} Z$z-Hx@%
} 7F`\Gz_2
k>i88^kPV
3M#x)cW
//打印回应的头信息 wgz]R
public void logResponseHead(HttpURLConnection con) 'o='Q)Dk
{ Df"PNUwA"
for(int i=1;;i++) PKlR_#EB?
{ {$S"Sj
String header=con.getHeaderFieldKey(i); lDS y$
if(header!=null) PqspoH 0OI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9Og
Utility.log(header+" : "+con.getHeaderField(header)); Wvb ~j
else &XNt/bK-?
break; m2SJ\1 J=
} 8UB2 du@?
} m%9Yo%l~
~n -N
r'noB<|e
public void splitterStop() II'.vp
{ Mg >%EH/'
bStop = true; GwO`@-}E
} :1d;jx>
]ty$/{hx'
k;qS1[a
} =2q#- ,t
ybpOk
"]3o933D
/* Aa-5k3:x]=
**FileAccess.java 5$i(f8*
*//文件访问(定位，写) Q 1i5"'][
package NetFox; 46M=R-7=
import java.io.*; 0aq{Y7sYU
foPM5+.G
NXLb'mH~
public class FileAccessI implements Serializable{ <IU
Sj)?!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qraq{'3
RandomAccessFile oSavedFile; ((?"2 }1r
long nPos; ZK?V{X{";
nVlZ_72d
%-YWn`yEm
public FileAccessI() throws IOException rhYARr'
{ D=LsoASVI
this("",0); S^q^=q0F
} `4ga~Ch
-^np"Jk
V6>{k_0{V
public FileAccessI(String sName,long nPos) throws IOException 9k4z__Ke
{ 'oGMr=gp<&
oSavedFile = new RandomAccessFile(sName,"rw"); EAh|$~X
this.nPos = nPos; -5os0G80
oSavedFile.seek(nPos); (gdzgLHy
} w@mCQ$
N f?\O@
C(sz/x?11
public synchronized int write(byte[] b,int nStart,int nLen) gjiS+N[
{ )#Ecm<.^
int n = -1; sw$JY}Q8x
try{ 7h.[eMLPB
oSavedFile.write(b,nStart,nLen); ?y%Mm09
n = nLen; 79Aa~+i'_
} 'mv|6Y
catch(IOException e) PTpfa*t
{ -R$Q`Xw
e.printStackTrace (); t&yuo E
} ?iaO+G&|
g5nL7;`N
p:|7d\r
return n; V+u0J"/8
} W$}2 $}r0U
AAi4} 8+\
(6)|v S
} $?&distJ
r"7 !J[u
|>JRJ"CFE
/* KrTlzbw&p\
**SiteInfoBean.java pfMmDl5|
*/ gE23C*!'&:
package NetFox; EBmkKiI;
V' sq'XB
o3'Za'N.
public class SiteInfoBean { 9WL$3z'*
{o%OG/!1
;A?86o'?
private String sSiteURL; //Site's URL 9*a"^
private String sFilePath; //Saved File's Path I_`$$-|
private String sFileName; //Saved File's Name Q-e(>=Gv_
private int nSplitter; //Count of Splited Downloading File $B )jSxSy
RHI?_gf&
. N5$s2t
public SiteInfoBean() 7$kTeKiP
{//nSplitter的缺省值为5 \NL*$SnxP
//default value of nSplitter is 5 &7w*=f8I
this("","","",5); wA";N=i=
} ATD4%|a9h
?J5E.7o
W>$mU&ew[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fc^d3wH0L
{ D' h%.
sSiteURL= sURL; |zp}u(N
sFilePath = sPath; 8J0#lu
sFileName = sName; )4FW~o<i
this.nSplitter = nSpiltter; \2[
{%v{iE>
U5;Y o+z
} Oz5Ze/HBN
E>1%7" i<
t|59/R
public String getSSiteURL() m>^#:JK
{ UmP\;
return sSiteURL; 6P`!yBAu
} HA;G{[X
`_.(qg
<)$JA
public void setSSiteURL(String value) O<+x=>_
{ aB~=WWLR\
sSiteURL = value; !@f!4n.e|I
} *qw//W
l7S&s&W @
jGKI|v4U(
public String getSFilePath() 6hf6Z3
{ '+\.&'A
return sFilePath; X8
} NfXEW-
l\t<_p/I)^
x|A{|oFC
public void setSFilePath(String value) x4/f5
{ X[$FjKZh=F
sFilePath = value; lm(k[]@
} 1y6{3AZm<
*l8:%t\
1|H(q
public String getSFileName() kSU]~x
{ 9>[*y8[:0
return sFileName; KOVR=``"/
} M>|R&v
7\Wq:<JL
PG'+vl
public void setSFileName(String value) Hge0$6l
{ bjB4
sFileName = value; F@kd[>/[
} gwv s
J4q_}^/2w
bv4G!21]*;
public int getNSplitter() vuNq7V*}
{ &265 B_'D
return nSplitter; VgcLG ]tE[
} 4{Af 3N
:B5M#D!dO
J=AF`[
public void setNSplitter(int nCount) 3YJa3fflK
{ =.8fES
nSplitter = nCount; W60C$*h
} @0U={qX
} s(shgI 3g
@_C?M5v
PNhxF C.
/* qfl#ki`,
**Utility.java b]xE^zM-I`
*/ zpBkP-%}E
package NetFox; [}Pi $at
S_dM{.!Z(,
><3!J+<?
public class Utility { }q D0-
9a3mN(<
oeIza<:=R
public Utility() GR>kxYM%q
{ IH$ZPux
;FO( mL(
u#~q86k
} xmBGZ4f%
ERz{, >G?
//线程睡眠 xfADks2w
public static void sleep(int nSecond) R.$1aqA}
{ {bD:OF
try{ k5/W'*P
Thread.sleep(nSecond); RA$q{$arb
} :DoE_
catch(Exception e) .}ePm(
{ n>\2_$uDI
e.printStackTrace (); lmpBf{~ S
} ;X)b=
} }`^DO Ar
~zph,bk
//日志 q3}WO]TBj
public static void log(String sMsg) } za"rU
{ ((cRe6
System.err.println(sMsg); O#72h]
} x_$`#m{hL5
}(/\vTn*1
jSd[
public static void log(int sMsg) wjc&S'[
{ ViYfK7Z
System.err.println(sMsg); uN+]q qCf
} 28x:]5=jb
} GiS:Nq`$(
i.Z iLDs\7
8Ai\T_l
/* 6'45c1e
**TestMethod.java 0AD8X+M{P
*/ (Qf. S{;
package NetFox; KGJ*h
EaKbG>
CWa~~h<r-
public class TestMethod { DVz_;m6)
14z ?X%
4~i?xo=;v
public TestMethod() hI 1or4V
{ ///xx/weblogic60b2_win.exe {@ Z=b5/P
try{ }*?,&9/_)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UU*v5&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l!mx,O`
SiteFileFetch fileFetch = new SiteFileFetch(bean); <rxtdI"3
fileFetch.start(); G.3yuok9
} NOFuX9/'w
catch(Exception e){e.printStackTrace ();} 5 BLAa1
<S3s==Cg
2{<o1x,Ym
} mI'&!@WG
lc\{47LwZ
3 #"!Hg
public static void main(String[] args) i2+_~$f
{ "p]!="\
new TestMethod(); @Yn+ir0>O
} U^8S@#1Q
} L%jIU<?Z7
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