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)); \85i+q:LuA
} gJXaPJA{
for(int i=0;i<nEndPos.length-1;i++) }OUtsh]y
{ AKC`TA*E
nEndPos = nStartPos[i+1]; \~W'v3:W
} 8=l%5r^cq
nEndPos[nEndPos.length-1] = nFileLength; cr3^6HB
} ,prf;|e?
} XTyxr
t# i#(H
b;n[mk
//启动子线程 az$FnVNn=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v+XJ*N[W
for(int i=0;i<nStartPos.length;i++) p2eGm-Erq
{ }tz7b#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [WmM6UEVS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ueudRb
nStartPos,nEndPos,i); G[=c Ss,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pP_LR ks}
fileSplitterFetch.start(); O-^Ma-}
} _XBd3JN@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )e{aN+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5+vaE 2v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D~m*!w*
nEndPos = " + nFileLength); qm}@!z^
// fileSplitterFetch[nPos.length-1].start(); d0D]Q
^!d3=}:0
vN:Ng
//等待子线程结束 >6T8^Nt
//int count = 0; )GpK@R]{
//是否结束while循环 d=(mw_-?
boolean breakWhile = false; LoV<:|GTI
jp,4h4C^)
K0~rN.C!0
while(!bStop) ?4,T}@P
{ 1?}T=)3+$
write_nPos(); DQ3<$0
Utility.sleep(500); dN q$}
breakWhile = true; h{Y",7]!
D7Z /H'|
gdc<ZYcM
for(int i=0;i<nStartPos.length;i++) 7#Ft|5$~q
{ tw;}jh
if(!fileSplitterFetch.bDownOver) 1Mzmg[L8
{ [JiH\+XLPs
breakWhile = false; f|5co>Hk
break; 7.Op<
} <E~'.p,
} X'srL j.
if(breakWhile) dV_G1'
break; ?`s8 pPc4
e6*8K@LHB
_>+Ld6.T6
//count++; lxx2H1([
//if(count>4) RZLq]8pM
// siteStop(); FrS]|=LJhX
} @"A4$`Xi3
N8jIMb'<
(QEG4&9
System.err.println("文件下载结束！"); Y2AJ+ |
} L *wYx|
catch(Exception e){e.printStackTrace ();} SUiOJ[5,
} q V=!ORuj
vh^VxS
(.:e,l{U%
//获得文件长度 pK*TE5]
public long getFileSize() I7onX,U+
{ 7Q 3k7
int nFileLength = -1; ?<!|
try{ ch]IzdD
URL url = new URL(siteInfoBean.getSSiteURL()); -?\D\\+t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2y4bwi
httpConnection.setRequestProperty("User-Agent","NetFox"); sJZiI}Xc
_BufO7`.
("KF'fp&M2
int responseCode=httpConnection.getResponseCode(); 1MFbQs^
if(responseCode>=400) /ZX}Nc g
{ ,1`z"7\W
processErrorCode(responseCode); pa+hL,w{6
return -2; //-2 represent access is error -"x$ZnHU
} mh%VrAq
F59 TZI
! nx{ X
String sHeader; &]Tmxh(
P \I|,
7V>M]
for(int i=1;;i++) [),ige
{ :FF=a3/"6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); " bG2:
//Utility.log(in.readLine()); JF]JOI6.e
sHeader=httpConnection.getHeaderFieldKey(i); bA 2pbjg=
if(sHeader!=null) qq?!LEZ
{ %T[]zJ(
if(sHeader.equals("Content-Length")) 4H/OBR
{ U$g?!Yl0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \V:^h[ad
break; z:O8Ls^\T
} pg.%Pdr<$
} ]e3Ax(i)
else DG/Pb)%Y
break; okXl8&mi
} 9WHddDA
} HW|IILFB
catch(IOException e){e.printStackTrace ();} [ ~,AfY
catch(Exception e){e.printStackTrace ();} kAx4fE[c
\e_O4
M|-)GvR$J
Utility.log(nFileLength); ICCc./l|
M5B# TAybC
KoYF]
return nFileLength; pAEx#ck
} ~[: 2I
*Ex|9FCt$
1YA% -~
//保存下载信息（文件指针位置） ;S{(]K7i
private void write_nPos() '-6~tWC~7
{ U*:!W=XN
try{ g0H[*"hj
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'qi}|I
output.writeInt(nStartPos.length); P>L +t`'
for(int i=0;i<nStartPos.length;i++) 58K5ZZG
{ RSds8\tk
// output.writeLong(nPos); )jj0^f1!j
output.writeLong(fileSplitterFetch.nStartPos); J,G lIv.A
output.writeLong(fileSplitterFetch.nEndPos); QJNFA}*>
} mOSv9w#,
output.close(); 4Hg9N}
} X]=t>
catch(IOException e){e.printStackTrace ();} ;<5q]/IHK
catch(Exception e){e.printStackTrace ();} R]dg_Da
} d-m7}2c
l:%GH
0YzpZW"+
//读取保存的下载信息（文件指针位置） V)^+?B)T
private void read_nPos() +p^u^a
{ neh(<>
try{ "b[5]Y{ U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b-y
int nCount = input.readInt(); !wNO8;(
nStartPos = new long[nCount]; l2d{ 73h
nEndPos = new long[nCount]; l0] EX>"E
for(int i=0;i<nStartPos.length;i++) 4 :=]<sc,
{ a?.=V
nStartPos = input.readLong(); @;kSx":b
nEndPos = input.readLong(); |}1dFp
} hph4`{T
input.close(); h![#;>(
} Jwp7gYZ
catch(IOException e){e.printStackTrace ();} M2|is ~
catch(Exception e){e.printStackTrace ();} CARzO7b\w
} l,:F
Q&&@v4L
JRFtsio*
private void processErrorCode(int nErrorCode) )+M0Y_r
{ hSMH,^Io$
System.err.println("Error Code : " + nErrorCode); [Q =Nn
} z~Q)/d,Ac
*A< 5*Db:F
ckn~#UE=
//停止文件下载 5uf a
public void siteStop() DMS!a$4
{ *H122njH+T
bStop = true; F/Pep?'
for(int i=0;i<nStartPos.length;i++) OZT.=^:A
fileSplitterFetch.splitterStop(); #%s#c0TX
t Pf40`@
fh{`Mz,o
} q;U,s)Uz^
} sGb{9.WK
//负责部分文件的抓取 yNc2@
**FileSplitterFetch.java KG@8RtHsQ
*/ &{RDM~
package NetFox; G j1_!.T
;]fs'LH
C7vxw-o|&p
import java.io.*; OTp]Xe/
import java.net.*; fV:83|eQ
AEuG v}#
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public class FileSplitterFetch extends Thread { eq"]%s
Ug`djIL
^&)|sP
String sURL; //File URL b2]Kx&!
long nStartPos; //File Snippet Start Position ^GX)Z~
long nEndPos; //File Snippet End Position mt`.6Xz~
int nThreadID; //Thread's ID h$=2p5'-
boolean bDownOver = false; //Downing is over 8[>zG2
boolean bStop = false; //Stop identical W`&hp6Jq
FileAccessI fileAccessI = null; //File Access interface L(o15
6,uX,X5
?8 {"x8W;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <X5fUU"+U
{ 4sM.C9W
this.sURL = sURL; h1{3njdr
this.nStartPos = nStart; ~v83pu1!2s
this.nEndPos = nEnd; kR9-8I{J
nThreadID = id; qa6,z.mQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jl<2>@
} lLD12d
Z= !*e~j@
a:S -
public void run() X(C$@N
{ PzGWff!*n
while(nStartPos < nEndPos && !bStop) [:V$y1
{ %UM *79
_~pbqa,
5PW^j\G-f
try{ rGkyGz8>
URL url = new URL(sURL); c)tfAD(N8x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \Roz$t-R|f
httpConnection.setRequestProperty("User-Agent","NetFox"); x`?3C"N:<
String sProperty = "bytes="+nStartPos+"-"; 4fzZ;2sl}
httpConnection.setRequestProperty("RANGE",sProperty); akT6^cP^
Utility.log(sProperty); >3_Gw4S*H
BZxvJQ
Q,9oKg
InputStream input = httpConnection.getInputStream(); "\=U)CJ
//logResponseHead(httpConnection); "vGW2~*)
D-4f.Tq4#
JLi|Td"1%
byte[] b = new byte[1024]; ty`DJO=Omj
int nRead; CP{cAzHO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @I*{f
{ |CzSU1ma
nStartPos += fileAccessI.write(b,0,nRead); ]_f<kW\1*
//if(nThreadID == 1) \4#W xZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EP+J N
} Lp7SLkwh3M
m`_ONm'T&
4aY|TN/|
Utility.log("Thread " + nThreadID + " is over!"); d/Q%IeEL.
bDownOver = true; )ANmIwmC#
//nPos = fileAccessI.write (b,0,nRead); [9 RR8
} EZj9wd"u
catch(Exception e){e.printStackTrace ();} 3Y~>qGQwh
} 9K&:V(gmw
} h}EPnC}
rbCAnwA2
7yba04D)
//打印回应的头信息 qv"$Bd:]r
public void logResponseHead(HttpURLConnection con) o lxByzTh>
{ JZ#[ 2mLh
for(int i=1;;i++) &M'*6A
{ [mHdG2X
String header=con.getHeaderFieldKey(i); [PM4k0YC8
if(header!=null) J")#I91
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ][]
Utility.log(header+" : "+con.getHeaderField(header)); 2|bn(QYz
else u4_9)P`]0
break; WT}H>T
} F\KUZ[%
} ,=:D
/SrAW`;"
J'2X&2
public void splitterStop() 6DWgl$[[
{ [h:T*(R?
bStop = true; ]d%8k}U
} +H Usz?
"}JZU!?
6x|jPb
} 9k~8
n}77##+R&C
2dzrRH
/* A={UL
**FileAccess.java p6WX9\qS(
*//文件访问(定位，写) 6i*sm.SDw
package NetFox; XGMiW0j0B
import java.io.*; Z`BK/:vo3H
- CWywuD
}#E[vRf
public class FileAccessI implements Serializable{ N"y)Oca{
_{Hj^}+$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4NIRmDEd
RandomAccessFile oSavedFile; S@ f9c
long nPos; {vO9ptR;
RAK-UN
{ buy"X4
public FileAccessI() throws IOException v6Vcjm
{ v]c6R-U
this("",0); /^|Dbx!u
} R^e.s -
s|B3~Q]
7`hP?a=
public FileAccessI(String sName,long nPos) throws IOException =6#Eh=7N
{ IyPnp&_
oSavedFile = new RandomAccessFile(sName,"rw"); F.v{-8GV
this.nPos = nPos; 1&o|TT/
oSavedFile.seek(nPos); a+PzI x2
} !7&5` q7
,-e{(L
.K<Q&
public synchronized int write(byte[] b,int nStart,int nLen) ED& `_h7?
{ /Qk4
int n = -1; kn"(A.R
try{ mo#04;VF
oSavedFile.write(b,nStart,nLen); bD8Gwi=iiu
n = nLen; 'oC) NpnH
} _H=Uwi_g
catch(IOException e) ~BkCp pI
{ }Ys>(w
e.printStackTrace (); AZ}Xj>=
} M[112%[+4
ohGfp9H
?8Cq{
return n; k,F6Tx
} xpx\=iAe
A6iq[b]
Nl(3Xqov
} fe#\TNeQJ[
D+7Rz_=
q=qcm`ce
/* Mzw X>3x
**SiteInfoBean.java H?y,ie#u
*/ *``JamnSO
package NetFox; Q({ r@*g
m<qJcZk
=k:,qft2
public class SiteInfoBean { ,$+V
yN s,Ll~
Vr1<^Ib
private String sSiteURL; //Site's URL e2W".+B1
private String sFilePath; //Saved File's Path ^4Ah_U
private String sFileName; //Saved File's Name 9Ly]DZ;L
private int nSplitter; //Count of Splited Downloading File qH6>!=00
L4|`;WP
Z@@K[$
public SiteInfoBean() fn6J*[`
{//nSplitter的缺省值为5 }t1a*z
//default value of nSplitter is 5 }sO&. ME
this("","","",5); \K]0JH
} FzXJ]H
eSmLf*\G
fGw9!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R= o2K
{ 1"M]3Kl
sSiteURL= sURL; :e%Pvk
sFilePath = sPath; 1!T1Y,w
sFileName = sName; =-lb)Z"d
this.nSplitter = nSpiltter; u21EP[[,
P0PWJ^+,+
f/Bp.YwL
} t=O8f5Pf{
KC#q@InK
8rS:5:Hi
public String getSSiteURL() X~,aNRy
{ _v=SH$O+
return sSiteURL; Q=20IQp
} z4]api(xZ
jc f #6
EeRX+BM,
public void setSSiteURL(String value) c[1oww
{ V0XvJ
sSiteURL = value; 9dUravC7
} t#pS{.I
z}ddqZ27G$
W=qVc
public String getSFilePath() o/Q;f@
{ !pdb'*,n
return sFilePath; KOuCHqCfq
} 25[I=ZdS
MsGM5(r:b
C"T;Qp~B
public void setSFilePath(String value) Nyj( 0W
{ ,1CIBFY
sFilePath = value; !XCm>]R
} xZwLlY
;Q*or2"!
2M'[,Xe
public String getSFileName() A/KJqiag
{ qC:raH_:
return sFileName; QTXt8I
} \\dMy9M-
| Aw%zw1@
Qq;Foa
public void setSFileName(String value) CZI66pDy
{ |NC*7/}
sFileName = value; :G2k5xD/E
} jesGV<`?l
Rt!FPoN,y
m6CI{Sa](l
public int getNSplitter() #& Rw&
{ {Um)15K
return nSplitter; tL)t" i
} 5Qn '
b@f$nS B
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public void setNSplitter(int nCount) CtAwBQO
{ u5: q$P
nSplitter = nCount; /qGf 1MHD
} \2"I;
} JYd 'Jp8bP
6ne7]RY
X_|J@5b7
/* +M$Q =6/
**Utility.java ;n=.>s*XL'
*/ HxK80mJ
package NetFox; 8'nVwb8I
t@N=kV
]d0tE?9
public class Utility { Sf7\;^
a\E:sPM'>
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public Utility() Z}l3l`h!
{ &6YIn|}
\uC15s<
u!X|A`o5i
} qHrA%k^!2O
NzSoqh{R
//线程睡眠 jWl)cC
public static void sleep(int nSecond) bc)~k:
{ xt%7@/hiE
try{ L3--r
Thread.sleep(nSecond); l6kWQpV
} aV?@s4
catch(Exception e) +hT:2TXn
{ )oPLl|=h
e.printStackTrace (); ruzspS
} 3?7\T#=
} bMMh|F
EzV96+
//日志 DV-;4AxxRq
public static void log(String sMsg) 0#&5.Gr)
{ [uq$5u
System.err.println(sMsg); ?$^2Umt0
} xScLVt<\e
PuT@}tw
lq&wXi
public static void log(int sMsg) YWe"zz
{ GlT7b/JCG
System.err.println(sMsg); Uo>]sNP~
} 2hkRd>)&5
} 5>j)kx=J9
i9A+gtd
[[Fx[
/* pDcjwlA%
**TestMethod.java tj4VWJK
*/ dhr3,&+T2
package NetFox; CS-uNG6
ayD}r#7
}mdAM6
public class TestMethod { ,Bo>E:u
I'iGt~4$
hn=[1<#^(
public TestMethod() qX
{ ///xx/weblogic60b2_win.exe Boz@bl mCB
try{ wl$h4 {L7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SNE#0L'}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V8-oYwOR
SiteFileFetch fileFetch = new SiteFileFetch(bean); Upd3-2kr&J
fileFetch.start(); #KXa&C
} ;b(p=\i
catch(Exception e){e.printStackTrace ();} ,%Up0Rr,
&PK\|\\2
Q|L9gz[?
} rJ{O(n]j
,JN8f]a^"g
yi%-7[*]=
public static void main(String[] args) %V{7DA&C
{ uYil ?H{kH
new TestMethod(); nwaxz>;
} ]=";IN:SU
} GBFtr
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