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)); 81|Xg5g)b
} BZE~k?*
for(int i=0;i<nEndPos.length-1;i++) /IC7q?avQN
{ l&4TfzkY
nEndPos = nStartPos[i+1]; rE bC_<
} @M-+-6+
nEndPos[nEndPos.length-1] = nFileLength; 4yH=dl4=44
} FPu"/4v&
} =,~h]_\_
:,=no>mMx
v&B*InR?+
//启动子线程 /0mbG!Ac
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )vK %LmP
for(int i=0;i<nStartPos.length;i++) B&`hvR
{ PQRh5km
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ( {H5k''
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \gL H_$}
nStartPos,nEndPos,i); 3~4e\xL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & ;+u.X
fileSplitterFetch.start(); 5B?>.4R
} wvm`JOP:A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |Y!#`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "S43:VH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KFd"JtPg
nEndPos = " + nFileLength); h&Ehp
// fileSplitterFetch[nPos.length-1].start(); Q-%Q7n'c
^Q]*CU+C
s45Y8!c
//等待子线程结束 Yo c N@s
//int count = 0; #s1O(rLRl
//是否结束while循环 vvLm9Tw
boolean breakWhile = false; "|<\\HR
_gB`;zo
lu(<(t,Lbs
while(!bStop) V,($I'&/
{ +xwz.:::
write_nPos(); p IXBJk
Utility.sleep(500); 5yO6szg
breakWhile = true; j3rBEQ,R
o)7gKWjujP
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for(int i=0;i<nStartPos.length;i++) tH<v1LEZN
{ ZgLO[Bj
if(!fileSplitterFetch.bDownOver) E{d Mdz
{ oQ 5g0(J~
breakWhile = false; iZQwo3"8r
break; ](vshgp2
} l/_3H\iM
} !=#E/il,
if(breakWhile) 3C8'0DB
break; rO/mK$
>'/G:\M>A
y5.Z<Y
//count++; G|yX9C]R
//if(count>4) Mu18s}
// siteStop(); 3mgFouX2x,
} vt[4"eU
8h~v%aZ1
uRKCvsisX
System.err.println("文件下载结束！"); A8hj"V47
} sf]y\_zU
catch(Exception e){e.printStackTrace ();} #"6(Q2| l
} EW1L!3K
&3>ki0L
-3X#$k8
//获得文件长度 )]!Ps` ,u
public long getFileSize() rB}UFS)
{ [syuoJ
int nFileLength = -1; I~MBR2$9
try{ yE-&TW_q:>
URL url = new URL(siteInfoBean.getSSiteURL()); @dcT8 YC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9tXLC|yl?
httpConnection.setRequestProperty("User-Agent","NetFox"); *"0Yr`)S
,qpn4`zE~
,-t3gc1~X
int responseCode=httpConnection.getResponseCode(); '!Vn
if(responseCode>=400) *~M=2Fj;i
{ <FMW%4
processErrorCode(responseCode); B}gi /
return -2; //-2 represent access is error nbw&+dcJ8
} x$AF0xFO
qJFBdJU(1
"tUXYY
String sHeader; 1^R@X
tsU.c"^n
//:.k#}~B
for(int i=1;;i++) h/`OG>./
{ Oe^3YOR#j{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,>2ijk#
//Utility.log(in.readLine()); ?b:J6(-
sHeader=httpConnection.getHeaderFieldKey(i); {Zjnf6d]
if(sHeader!=null) |v}"UW(y
{ tz&=v,_jc
if(sHeader.equals("Content-Length")) \^?BC;s^C
{ }?#<)|_5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \rcbt6H
break; 6J6MR<5'
} {LY$
} :HRJ49a
else XY1NTo.=
break; on(F8%]zE
} z}s0D]$+x
} ?.IT!M}DR
catch(IOException e){e.printStackTrace ();} y)|Q~8r
catch(Exception e){e.printStackTrace ();} E*7B5
4CS9vv)9R
`l1{BU
Utility.log(nFileLength); ]}8<h5h)
._-^58[
2<yi8O\
return nFileLength; _C&2-tnp
} -fz |
[sTr#9Z
5P -IZ8~$
//保存下载信息（文件指针位置） U{RW=sYB~9
private void write_nPos() S,lJ&Rsu
{ 3otia;&B
try{ #DwTm~V0"
output = new DataOutputStream(new FileOutputStream(tmpFile)); >yg mE`g
output.writeInt(nStartPos.length); 9cWl/7;zXO
for(int i=0;i<nStartPos.length;i++) WcPDPu~/
{ ,JN2q]QPP
// output.writeLong(nPos); fg%I?ou
output.writeLong(fileSplitterFetch.nStartPos); kG &.|
output.writeLong(fileSplitterFetch.nEndPos); kW4/0PD
} U'UV=:/-
output.close(); }/[tB
} G7pj.rQ
catch(IOException e){e.printStackTrace ();} 8}\VlH]
catch(Exception e){e.printStackTrace ();} .Frc:Y{
} R?Ki~'k=
B+iVK(j'[v
26yv w
//读取保存的下载信息（文件指针位置） '73dsOTIT
private void read_nPos() MJV)| 2C
{ Iujly f
try{ ?a7PxD.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jB:$+k|~.
int nCount = input.readInt(); *&+e2itmp
nStartPos = new long[nCount]; X7?p$!M6;B
nEndPos = new long[nCount]; 9loWh5_1Z
for(int i=0;i<nStartPos.length;i++) |zKe*H/
{ kUmrJBh$
nStartPos = input.readLong(); \^iJv~d
nEndPos = input.readLong(); rm;'/l8Y-E
} VThcG( NF
input.close(); cTHSPr?<
} xpx=t71Hq
catch(IOException e){e.printStackTrace ();} y!6B Gz
catch(Exception e){e.printStackTrace ();} ANc)igo
} x:88E78
7;#9\a:R?
{xW?v;
private void processErrorCode(int nErrorCode) $}jp=?,t
{ 7$<.I#x
System.err.println("Error Code : " + nErrorCode); CuR\JKdRo
} F.HD;C-;(
v98=#k!F
5:Pp62
//停止文件下载 xKWqDt
public void siteStop() /WRS6n
{ Yewn
bStop = true; Al09R,I;
for(int i=0;i<nStartPos.length;i++) wV+ W(
fileSplitterFetch.splitterStop(); }tF/ca:XPQ
@H= d8$
]iRE^o6
} h=.|!u
} wdS^`nz|
//负责部分文件的抓取 NKvBNf|D
**FileSplitterFetch.java K}tl,MMU
*/ a*$to/^r
package NetFox; MIo<sJuv
P,k~! F^L
K]Q#B|_T
import java.io.*; 8i!AJF9IQ}
import java.net.*; :'91qA%Wr
J0*hJ-/u
S_/9eI~X
public class FileSplitterFetch extends Thread { .+MJ' bW
_Db=I3.HJ
y >r7(qg
String sURL; //File URL K*&M:u6E
long nStartPos; //File Snippet Start Position S<rdPS*P
long nEndPos; //File Snippet End Position au@ LQxKQ
int nThreadID; //Thread's ID ,;)Y1q}Q
boolean bDownOver = false; //Downing is over }l~|c{WH`
boolean bStop = false; //Stop identical L^i=RGx
FileAccessI fileAccessI = null; //File Access interface Nz_c]3_j
M$~3`n*^
$m,gQV~4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cjAKc|NJ
{ <`k\kZM
this.sURL = sURL; Ni#!C:q
this.nStartPos = nStart; {e\Pd!D?|
this.nEndPos = nEnd; lPx4=O
nThreadID = id; /ts=DxCC;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 11[[HkX@
} 7zXFQ|TP
v#0F1a?]D
8^\}\@
public void run() {STOWuY
{ 4e~^G
while(nStartPos < nEndPos && !bStop) u.sF/T=6f
{ R*a5bKr
d9>*a$x;/
#"-?+F=rk
try{ 5Ds/^fA
URL url = new URL(sURL); 0D/u`-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (|)`~z
httpConnection.setRequestProperty("User-Agent","NetFox"); c[\ :^w^I6
String sProperty = "bytes="+nStartPos+"-"; 4YDK`:4I~
httpConnection.setRequestProperty("RANGE",sProperty); ~XN--4%Q
Utility.log(sProperty); =}>wxO
uPKq<hBI
<_$]!Z6UR
InputStream input = httpConnection.getInputStream(); ?j;e/r.
//logResponseHead(httpConnection); (MhC83|?
&IsQgS7R
=M'M/vKD
byte[] b = new byte[1024]; PLU8:H@X
int nRead; +^ a9i5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bP\0S@1YL
{ QA>(}u\+
nStartPos += fileAccessI.write(b,0,nRead); DX GClH
//if(nThreadID == 1) VN[C%C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 59mNb:<
} 5OeTOI()&5
)]WWx-Uf'
`Fa49B|`D
Utility.log("Thread " + nThreadID + " is over!"); gwhd) .*
bDownOver = true; 1{l18B`
//nPos = fileAccessI.write (b,0,nRead); cKuU#&FaV
} kR$>G2$!
catch(Exception e){e.printStackTrace ();} Wt5x*p-!C
} OLh`R]Sd
} |$"2R3
nX4R
]T|9>o!
//打印回应的头信息 Xou1X$$z
public void logResponseHead(HttpURLConnection con) [p[nK=&r
{ j(^ot001%v
for(int i=1;;i++) (Cjnf a 2
{ ^7MhnA
String header=con.getHeaderFieldKey(i); &7Frg`B&:
if(header!=null) AzAD76iNv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \$:KfN>WY
Utility.log(header+" : "+con.getHeaderField(header)); Fx,08
else ^2f'I iE
break; HDQhXw!!hc
} I@Zd<Rn
} <X[TjP
'F%4[3a$\n
Z|;<:RKWY
public void splitterStop() _svEPHU
{ h'VN& T,
bStop = true; ?_mcg8A@@*
} (ii6w d<*
x,$N!X
J-*&&
} W}m-5L
! |SPOk
qu]ch&"?U
/* b`"E(S/
**FileAccess.java Ci%u =%(
*//文件访问(定位，写) o?nlnoe
package NetFox; M|!^ #!a(
import java.io.*; L9tjHC]
}OY]mAv-B
5/x"!Jk
public class FileAccessI implements Serializable{ sX&.8
0dS}pd">k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .5Y%I;~v
RandomAccessFile oSavedFile; EvZ;i^.8LS
long nPos; s ^NO(
FTM(y CN
Jf\lnJTyU8
public FileAccessI() throws IOException hZGoiWC
{ d:/8P985
this("",0); vZV+24YWb
} .G}E
D|8vS8p
m-f"EFmP
public FileAccessI(String sName,long nPos) throws IOException A ?"(5da.
{ _&S?uz m
oSavedFile = new RandomAccessFile(sName,"rw"); ;>^oe:@
this.nPos = nPos; iku8T*&uc
oSavedFile.seek(nPos); a<X8l^Ln
} tX;00g;U.
4d&#NP
kp3(/`xP
public synchronized int write(byte[] b,int nStart,int nLen) _\E{T5
{ Gvo(iOU
int n = -1; @$FE}j_
try{ (]7*Kq
oSavedFile.write(b,nStart,nLen); 3wXmX
n = nLen; >Gbj1>C}
} n^|;J*rD
catch(IOException e) lB!`,>"c
{ vW4~\]
e.printStackTrace (); -r/G)Rs
} <>aBmJs4
5 e:Urv77
b *IJ +
return n; B{|g+c%
} /CpUq;^
3/IQ]8g"
gLv|Hu7
} `abQlBb*
j]7|5mC78
[vki^M5i|Z
/* ?]%JQ]Gf*
**SiteInfoBean.java xsK{nM6g
*/ :LRR\v0HM
package NetFox; TJ(PTB;
_'&N01
'!`%!Xg
public class SiteInfoBean { e;b,7Qw
~82[pY
o?\)!_Z|
private String sSiteURL; //Site's URL Ore$yI}!m
private String sFilePath; //Saved File's Path UnNvlkjq9
private String sFileName; //Saved File's Name )#-27Y
private int nSplitter; //Count of Splited Downloading File <*L=u;
7L)1mB.
tB.;T0n
public SiteInfoBean() =jD[A>3I
{//nSplitter的缺省值为5 RAR0LKGX
//default value of nSplitter is 5 7t-j2 n`<
this("","","",5); "^-U#f>k
} M9Gs^
.4={K)kz|F
~`2w ul
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pTq,"}J!+
{ U -~%-gFC
sSiteURL= sURL; GypZ!)1
sFilePath = sPath; 8xhXS1
sFileName = sName; GZT}aMMSJ
this.nSplitter = nSpiltter; PpMZ-f@
'|^LNAx
dJ\6m!Mp
} A9PXu\%y
,oe e'
PJj{5,#@3
public String getSSiteURL() =/=x"q+X
{ 2{s ND
return sSiteURL; J<DV7zV
} b~06-dk1
ulFU(%&
iHjo3_g)n
public void setSSiteURL(String value) eux_tyC
{ w?ssV
sSiteURL = value; IV^LYu
} XuJwZN!(
5_Yv>tx
BOJh-(>I
public String getSFilePath() oTtmn, T
{ vl$! To9R"
return sFilePath; Wm:3_C +j
} Pb?H cg
mm$D1=h{|
YVVX7hB
public void setSFilePath(String value) 7ka^y k@Q
{ OXDlwbwL
sFilePath = value; ))c;DJc
} lp[3z&u
c?) pn9
6A M,1
public String getSFileName() l^xkXj
{ qGkrG38K
return sFileName; _yjM_ALjo
} L*tXy>&b.
kN9S;o@)
X@+:O-$
public void setSFileName(String value) $}oQ=+c5
{ e<5+&Cj
sFileName = value; N&NOh|YS
} V2es.I
:{4G=UbAI
G_5sF|(mq
public int getNSplitter() OxElvbM#
{ +C;ZO6%w
return nSplitter; )|LX_kyW
} /og}e~q
MIa].S#
<0P`ct0,i
public void setNSplitter(int nCount) EC1q#;:
{ ,2JqX>On>Y
nSplitter = nCount; )$q<"t\#P#
} fLI@;*hL0
} xy mK|
qU8UKIP
VR?7{3
/* <6<uO\B\
**Utility.java w:FH2*
*/ &_4A6
package NetFox; }=A6Jv(j
T.ub!,Y
:&yRvu
public class Utility { !Go(8`>
|L;'In
:EgdV
public Utility() CW\o>yh
{ /p\Ymq
=@pm-rI|-
xHsH .f_{
} `^AbFV 3
`H$s-PX
//线程睡眠 lk.Q6saI1
public static void sleep(int nSecond) F/j=rs,*|D
{ @PwEom`a
try{ ?]fBds=
Thread.sleep(nSecond); 7P/j\frW
} IX7d[nm39
catch(Exception e) Ccz:NpK+
{ ';aPoaO %
e.printStackTrace (); x(}tr27o
} I.x0$ac7
} ~$r^Ur!E\
8YkP57Y%[Z
//日志 74gU4T
public static void log(String sMsg) #PXl*~PrQ/
{ bDUGzezP<
System.err.println(sMsg); $L</{bXW
} {(a@3m~a%
3kR- WgVF,
^Jnp\o>
public static void log(int sMsg) R2]?9\II
{ :NbD^h)R
System.err.println(sMsg); O.rk!&N
} ac+7D:X
} +Yi=Wo/
oeIB1DaI
XQj`KUO@
/* 5\|[)~b
**TestMethod.java Br#]FB|tD
*/ ] {NY;|&I'
package NetFox; ,6t0w|@-k
aF'Ik XG d
g?=B{V
public class TestMethod { }d.R=A9L
W@wT,yJ8@
Gw+z8^|C&}
public TestMethod() EVq<gGy
{ ///xx/weblogic60b2_win.exe S}Mxm2
try{ !@VmaAT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kjz,p^Y\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (|U+(~PJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); t9m`K9.\
fileFetch.start(); s ^)W?3t]
} FNc[2sI
catch(Exception e){e.printStackTrace ();} ZLL0 6p
Nq*\{rb
0w+hf3K+:
} bO2$0!=I
k9^P#l@p
[j93Mp
public static void main(String[] args) Q8:u1$}
{ U +mx@C_
new TestMethod(); ' J-(v
} _|A)ueY
} Z]SCIU @+
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