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)); SdJ/4&{ !
} )DT|(^
for(int i=0;i<nEndPos.length-1;i++) 9JnY$e<&
{ =X-Tcj?3g
nEndPos = nStartPos[i+1]; %WGuy@tL
} ZCYS\E7X
nEndPos[nEndPos.length-1] = nFileLength; &:3Z.G
} _1L(7|^~y[
} R?pRxY
!^y y0`k6
jQ=~g-y
//启动子线程 +7U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nX^1$')gp
for(int i=0;i<nStartPos.length;i++) {q3:Z{#>7
{ ~e">_;k6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +th%enRB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bA@P}M)X
nStartPos,nEndPos,i); e;VIL 2|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kesy2mE
fileSplitterFetch.start(); s+Q;pRZW{
} )R?;M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]]BOk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {2 %aCCV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F[Q!d6
nEndPos = " + nFileLength); j U[ O
// fileSplitterFetch[nPos.length-1].start(); a{'Z5ail
@I-Lv5
E4i0i!<z
//等待子线程结束 QA;!caNp
//int count = 0; Tycq1i^
//是否结束while循环 W3rl^M=r
boolean breakWhile = false; eZLMP
o''wCr%
iY0>lDFm.
while(!bStop) aWy]9F&C:
{ wX,F`e3"/
write_nPos(); ;%Hf)F
Utility.sleep(500); 'dJ/RJ~
breakWhile = true; G7@O`N8'
wRtZ`o
/i_ @
for(int i=0;i<nStartPos.length;i++) rwE%G>Vb
{ 7N=-Y>$X
if(!fileSplitterFetch.bDownOver) ROc`BH=
{ iv&v8;B
breakWhile = false; q,%:h`t\
break; cz/Q/%j$/
} hhI)' $
} jrMe G.e=D
if(breakWhile) }uY!(4Rw
break; VDbI-P&c
p$E8Bn%[
} JiSmi6o
//count++; -\,zRIOK
//if(count>4) o "z@&G" ^
// siteStop(); dy>!KO
} bh p5<N
Uf\nFB? ^
XfYC7-e9c
System.err.println("文件下载结束！"); j&R+2%
} W# US#<9Y
catch(Exception e){e.printStackTrace ();} Te,$M3|
} 9QC.TG@
;GGK`V
'gso'&Uaj
//获得文件长度 :dI\z]Y(
public long getFileSize() CC^E_jT
{ @b#^ -
int nFileLength = -1; k1 -~
try{ #Q"O4 b:8
URL url = new URL(siteInfoBean.getSSiteURL()); FFKGd/:!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \ I`p|&vG
httpConnection.setRequestProperty("User-Agent","NetFox"); 3)=c]@N0
u3 0s_\
28.~iw
int responseCode=httpConnection.getResponseCode(); xiblPF_n3
if(responseCode>=400) .TJEUK
{ :9t4s#.
processErrorCode(responseCode); a->3`c
return -2; //-2 represent access is error XT>.`, sv
} e8=YGx^o`
R&f^+0%f
-O!/Jv"{,[
String sHeader; rN)V[5R#M
gJ$K\[+
I@#;nyAj"
for(int i=1;;i++) 6NWn(pZ]p
{ _~u2: yl(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c]-*P7W
//Utility.log(in.readLine()); )!BsF'uVQ
sHeader=httpConnection.getHeaderFieldKey(i); SQ*k =4*r
if(sHeader!=null) bi4f]^hQz
{ A]0:8@k5
if(sHeader.equals("Content-Length")) !p/%lU65
{ 8;14Q7,S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vr[czfROz'
break; \!]hU%Un
} kX`[Y@nUN
} q@hzo>[
else K14^JAdY/
break; M=qb^~ l
} 1 rs&74-
} DV)3
catch(IOException e){e.printStackTrace ();} pCh2SQ(Q>
catch(Exception e){e.printStackTrace ();} `o]g~AKX
C'yppl%
nrm+z"7
Utility.log(nFileLength); j^tW Iz
39wa|:I
sZ,Y60s8a
return nFileLength; L"jY+{oLIJ
} 7{@l%jx][
($w@Z/;
0& >H^
//保存下载信息（文件指针位置） SP*fv`
private void write_nPos() 1923N]b
{ Y6i _!z[V[
try{ G;NF5`*4mc
output = new DataOutputStream(new FileOutputStream(tmpFile)); dovZ#D@Q
output.writeInt(nStartPos.length); ]?O2:X
for(int i=0;i<nStartPos.length;i++) @Jm7^;9/
{ /S5|wNu
// output.writeLong(nPos); <@wj7\pQ
output.writeLong(fileSplitterFetch.nStartPos); 9,j-Vp!G
output.writeLong(fileSplitterFetch.nEndPos); [r+ZE7$2b"
} hpTDxh'?$C
output.close(); :cu#V
} qyC=(v
catch(IOException e){e.printStackTrace ();} 'r1LSht'
catch(Exception e){e.printStackTrace ();} )^||\G
} zDhB{3-Q1{
H{J'# 9H
g~V+4+
//读取保存的下载信息（文件指针位置） GdV1^`M6
private void read_nPos() ~Tbj=f
{ ~qe%Yq
try{ 7dsefNPb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8 C[/dH
int nCount = input.readInt(); fb8%~3i>
nStartPos = new long[nCount]; vAY,E=&XvM
nEndPos = new long[nCount]; 2(5ebe[
for(int i=0;i<nStartPos.length;i++) 1f",}qe;
{ n -(
nStartPos = input.readLong(); kKC9{^%)
nEndPos = input.readLong(); `.s({/|[
} .ERO|$fv
input.close(); f&v9Q97=
} *5w{8
catch(IOException e){e.printStackTrace ();} 4_Dp+^JF
catch(Exception e){e.printStackTrace ();} ()&~@1U
} ^B8b%'\
CLvX!O(~
l Va &"
private void processErrorCode(int nErrorCode) r.7$&BCng
{ rZ8`sIWQt
System.err.println("Error Code : " + nErrorCode); ODZ|bN0>
} bfo["
lHgs;>U$
Q.K,%(^;a
//停止文件下载 cGjPxG;
public void siteStop() vfVj=DYj
{ 8@so"d2e
bStop = true; y;/VB,4V
for(int i=0;i<nStartPos.length;i++) (o3 Iy
fileSplitterFetch.splitterStop(); jKt7M>P
Eke5Nb
|:8bNm5[
} 2-Y<4'>
} ;b-XWK=
//负责部分文件的抓取 !K|5bK
**FileSplitterFetch.java mI74x3 [
*/ <b,~:9*?
package NetFox; oudxm[/U
D3|I:Xm
9on@Q_7m
import java.io.*; ~69&6C1Ch
import java.net.*; w@,zFV
P.gb1$7<
]U"94S U:)
public class FileSplitterFetch extends Thread { bhniB@<
H;RwO@v
N7e"@Ic
String sURL; //File URL 03C0L&
long nStartPos; //File Snippet Start Position ]+X@ 7
long nEndPos; //File Snippet End Position t.mVO]dsj
int nThreadID; //Thread's ID -GxaV #{
boolean bDownOver = false; //Downing is over m*JaXa
boolean bStop = false; //Stop identical g+z1
FileAccessI fileAccessI = null; //File Access interface UX7t`l2R
XI^QF;,
5oAK8I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X&kp;W
{ Y]&j,j&
this.sURL = sURL; l\i)$=d&g
this.nStartPos = nStart; Bz,?{o6s)Q
this.nEndPos = nEnd; ](hE^\SC
nThreadID = id; KCs[/]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4EY)!?;
} h$2</J"
#\=FO>
%7|9sQ:
public void run() rW$[DdFA5{
{ s0vDHkf8
while(nStartPos < nEndPos && !bStop) \-g)T}g,I
{ |ZmUNiAa
<7~'; K
q<M2,YrbAI
try{ nrjE.+v
URL url = new URL(sURL); a|X a3E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /'/Xvm3
httpConnection.setRequestProperty("User-Agent","NetFox"); PUUwv_
String sProperty = "bytes="+nStartPos+"-"; B6={&7U2
httpConnection.setRequestProperty("RANGE",sProperty); 'dn]rV0(C
Utility.log(sProperty); ez|)ph7
]9^sa-8
~sh`r{0
InputStream input = httpConnection.getInputStream(); 1jcouD5?H
//logResponseHead(httpConnection); }~L.qG
{tWf
^~etm
byte[] b = new byte[1024]; ')cMiX\v
int nRead; P5UL4uyl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :.Wr{"`
{ {z{bY\
nStartPos += fileAccessI.write(b,0,nRead); yK=cZw%D
//if(nThreadID == 1) .6Pw|xu`Pw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (JOgy.5C~
} I`!<9OTBj
DW[N|-L
Vh4X%b$TV
Utility.log("Thread " + nThreadID + " is over!"); BI%$c~wS
bDownOver = true; JJN.ugT}1
//nPos = fileAccessI.write (b,0,nRead); %lGl,me H
} :/nj@X6
catch(Exception e){e.printStackTrace ();} cPlZXf
} H*PSR
} ;{N!Eb`S
fumm<:<CLO
U2W|:~KM
//打印回应的头信息 SHfy".A6.0
public void logResponseHead(HttpURLConnection con) \XZ/v*d0
{ ds<2I,t
for(int i=1;;i++) ``hf=`We
{ ~x1$h#Cx'
String header=con.getHeaderFieldKey(i); !2f[}.6+
if(header!=null) asppRL||
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8.O8No:'&
Utility.log(header+" : "+con.getHeaderField(header)); I=`U7Bis"
else V@g'#={r
break; ,s"^kFl
} #V~me
} a.k.n<
f*?]+rz
iP7(tnlW$
public void splitterStop() zBzZxK>$
{ n-tgX?1'
bStop = true; \!.B+7t=I
} UM"- nZ>[
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+nFu|qM}
} W{ q U
!Wntd\w
KW pVw!
/* <h0?tv]
**FileAccess.java rlOAo`hd
*//文件访问(定位，写) t-tg-<
package NetFox; 8p 'L#Q.
import java.io.*; g}1B;zGf
\@c,3
4V)kx[j
public class FileAccessI implements Serializable{ TNe l/
P@V0Mi),
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8V`WO6*
RandomAccessFile oSavedFile; 6d<r= C=
long nPos; aC8} d
65JF`]
V]lLw)
public FileAccessI() throws IOException KQ% GIz x
{ {k TEHe
this("",0); .ypL=~Rp
} $9_xGfx}
$r@zs'N
6]WAUK%h
public FileAccessI(String sName,long nPos) throws IOException "jKY1*?
{ t%/&c::(6
oSavedFile = new RandomAccessFile(sName,"rw"); JcsHt;
this.nPos = nPos; Z&+ g;(g
oSavedFile.seek(nPos); /[ 5gX^A
} On9A U:\
m$>H u@Va
Rq'S>#e
public synchronized int write(byte[] b,int nStart,int nLen) PR#exm&
{ +>6iYUa
int n = -1; gwuI-d^
try{ o,\$ZxSlm
oSavedFile.write(b,nStart,nLen); :+^lJ&{U
n = nLen; Tztu}t]N
} a/4T>eC
catch(IOException e) '}53f2%gKa
{ ?jv/TBZX4
e.printStackTrace (); $]/{[@5
} N2^=E1|_
5y.WMNNv{
MzdV2.
return n; & p
} /|6N*>l)y
/$Nsd
V1N3iI
} }c,}V
24 'J
[.7d<oY
/* xX&+WR
**SiteInfoBean.java %HhnSi1K
*/ i#n0U/
package NetFox; M6"PX *K
SaO}e
-V77C^()8d
public class SiteInfoBean { iy.p n
@alK;\
C_}]`[
private String sSiteURL; //Site's URL UmP/h@8
private String sFilePath; //Saved File's Path @1roe G
private String sFileName; //Saved File's Name _aSxc)?
private int nSplitter; //Count of Splited Downloading File C2kPMB=Xo
G5BfNU
S6DKREO
public SiteInfoBean() Ko<:Z)PS
{//nSplitter的缺省值为5 U)o-8OEZ9
//default value of nSplitter is 5 jp%S3)
this("","","",5); e'NJnPO
} ~w+c8c8pW
AlaW=leTe
cA?W7D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AofKw
{ I5p? [
sSiteURL= sURL; 2*& ^v
sFilePath = sPath; q 'yva
sFileName = sName; ?(1y
this.nSplitter = nSpiltter; rH Lm\3
&jJL"gq"
6Pl<'3&
} MAR'y8I
Gx/Oi)&/
ASA,{w]
public String getSSiteURL() m.rmM`
{ +Mb.:_7'
return sSiteURL; dFB]~QEK
} GR_-9}jQP
(mpNcOY<D
z43M]P<
public void setSSiteURL(String value) m=:9+z
{ 'o2Fa_|<#
sSiteURL = value; Dw.J2>uj
} m+[Ux{$
c7k~S-nU
H/ HMm{4
public String getSFilePath() C ;W"wBz9
{ lTgjq:mn
return sFilePath; gPI ?C76
} p8O2Z?\
$7ZX]%<s
x|Bf-kc[#Q
public void setSFilePath(String value) 1.GQau~
{ sY&IquK^
sFilePath = value; n b?lTX~
} *i%.;Z"
%5n_ p^xp
Xl#ggub?
public String getSFileName() E{`fF8]K
{ r),kDia
return sFileName; IOmfF[
} .t!x<B
+I|vzz`ZVr
KkbDW3-
public void setSFileName(String value) 7Ovi{xd@
{ ^jZbo{
sFileName = value; m<Dy<((_I
} FTUv IbT
|/{=ww8|
VlsnL8DV
public int getNSplitter() f.$af4 u
{ .M%}X7
return nSplitter; qo bc<-
} *.t7G
Zb>?8
<\^8fn
public void setNSplitter(int nCount) f2`2,?
{ VY4yS*y
nSplitter = nCount; sDlO#
} aEeodA<(
} Z@!+v19^
mz0X3
hRhe& ,v
/* YNF k
**Utility.java 7Ak6,BuI%
*/ x'<X!gw
package NetFox; U'bEL^Jf
?Z/V~,
.#8 JCY
public class Utility { @*((1(q
1oGw4kD^x
8<Av@9 *}
public Utility() q@8*Xa>
{ jQB9j
Tyx_/pJT
/82b S|
} s.C_Zf~3
aqk!T%fg
//线程睡眠 UZ+<\+q3^
public static void sleep(int nSecond) M .mfw#*
{ YIYmiv5
try{ EaN6^S=
Thread.sleep(nSecond); ZUd-<y
} r;N|)
catch(Exception e) u'BaKWPS
{ (*iHf"=\
e.printStackTrace (); [{,1=AB
} `[ir}+S
} CLRdm^B
SwMc pNo
//日志 XwaXdvmK
public static void log(String sMsg) q(84+{>B
{ vr=#3>
System.err.println(sMsg); +CNv l
} ( a#BV}=
v.qrz"98-
&tj!*k'
public static void log(int sMsg) P&LsVR{#
{ DB,J3bm
System.err.println(sMsg); zTU0HR3A
} }qD\0+`qi
} .$vK&k
7qS)c}Q\
Y}wyw8g/
/* G4"F+%.
**TestMethod.java 5r^(P
*/ Cw&KVw*
package NetFox; G"A#Q"
WH^%:4
a\*yZlXKs
public class TestMethod { 5nx1i
w``U=sfmV
>^3i|PB
public TestMethod() Qo|\-y-#
{ ///xx/weblogic60b2_win.exe PCtzl)
try{ sFRQe]zCcP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u>vL/nI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (#c:b
SiteFileFetch fileFetch = new SiteFileFetch(bean); vnuN6M{
fileFetch.start(); Ig{0Z">
} f3y=Wxk[
catch(Exception e){e.printStackTrace ();} sRb9`u=)
}Zp,+U*"
|2A:eI8 ^
} SOIN']L|V[
do'GlU oMC
)vlhN2iv
public static void main(String[] args) rYk0 ak
{ wUJcmM;
new TestMethod(); r5^eNg k
} k+*u/neh
} x]j W<A
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