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)); ~w}=Oby'y
} <|hrmwk|
for(int i=0;i<nEndPos.length-1;i++) R0-Y2v
{ zO0K*s.yK
nEndPos = nStartPos[i+1]; c,#Nd@
} @[{5{ y
nEndPos[nEndPos.length-1] = nFileLength; Ti>}To}B5
} +R"n_6N
} IH.EvierJ
fr&p0)85>B
j_S3<wEJ
//启动子线程 *E-MJCv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i#PR Tbc
for(int i=0;i<nStartPos.length;i++) mB%m<Zo\U
{ ( geV(zT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N]&hw&R{Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /buj(/q^#
nStartPos,nEndPos,i); nPH\Lra
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $9Gra#
fileSplitterFetch.start(); !(y(6u#
} Bf" ZmG9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gl!ht@;>ak
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {~#d_!(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uxL3 8d]
nEndPos = " + nFileLength); Uh'W d_?
// fileSplitterFetch[nPos.length-1].start(); >2NsBS(
YB(8 T"
k7M{+X6[
//等待子线程结束 7**zO3 H
//int count = 0; ::@JL
//是否结束while循环 #z}0]GJKj
boolean breakWhile = false; U@:l~xJ
<"av /`;
@.pr}S/
while(!bStop) jH<,dG:{
{ (@S9>z4s
write_nPos(); &uI33=
Utility.sleep(500); JY_!G
breakWhile = true; %cASk>^i
Bo ??1y
|C>\ku*
for(int i=0;i<nStartPos.length;i++) -o57"r^x
{ 1U ='"
if(!fileSplitterFetch.bDownOver) ~eUv.I/
{ {'#7b# DB>
breakWhile = false; ;|f]e/El
break; |RDE/
} M`xI N~
} 4thPR}DH}
if(breakWhile) `R*!GHro
break; jEK{47i v
id]}10
,/[1hhP@
//count++; Ld=6'C8ud
//if(count>4) Vc+~yh.)
// siteStop(); ;}k_
} T;i+az{N:V
f|2QI~R
~O 4@b/!4
System.err.println("文件下载结束！"); 3w! NTvp
} z'0 =3
catch(Exception e){e.printStackTrace ();} S(:|S(
} Az/P;C=
[ * !0DW`
<<H'Z
//获得文件长度 H-8_&E?6m
public long getFileSize() Htep3Ol3
{ |^#Z!Hp_Y
int nFileLength = -1; 5e2yJ R
try{ d!"gb,ec
URL url = new URL(siteInfoBean.getSSiteURL()); mOb@w/f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s+v$sF
httpConnection.setRequestProperty("User-Agent","NetFox"); }RQ'aeVl(
?:W=ddg
yaAg!mW
int responseCode=httpConnection.getResponseCode(); q'jInwY|x
if(responseCode>=400) WctGhGH
{ B*fBb.Z
processErrorCode(responseCode); !ce,^z&5
return -2; //-2 represent access is error A \Z_br
} G ahY+$L,
c43&[xPLz
q4Y'yp`?K;
String sHeader; UO-,A j*wW
%gTY7LIe1z
I!.-}]k
for(int i=1;;i++) UBx0Z0Y
{ zZS,<Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d)0 hAdh
//Utility.log(in.readLine()); epP_~TU
sHeader=httpConnection.getHeaderFieldKey(i); _ sBFs.o
if(sHeader!=null) D~,iI7ac
{ TH+TcYqO
if(sHeader.equals("Content-Length")) CDDEWVd
{ hxGo~<. :
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `[tYe<
break; QtOT'<2t]
} RG-,<G`
} ST\d-x
else T"E%;'(cp)
break; 3.%jet1
} PH!rWR
} C0L(ti;
catch(IOException e){e.printStackTrace ();} yI's=Iu`
catch(Exception e){e.printStackTrace ();} l+?sR<e?!
6Q`7>l.|?
9A}nZ1Y
Utility.log(nFileLength); 83Fmu/(
8+~'T|
;5}"2hU>
return nFileLength; r4 ;nkx
} Chtls;Ph[
ET|4a(x
,D`\ RV
//保存下载信息（文件指针位置） S?Uvt?
private void write_nPos() JwUz4
{ ;zi4W1
try{ OPDRV\
output = new DataOutputStream(new FileOutputStream(tmpFile)); F/D/1w^ iR
output.writeInt(nStartPos.length); |LE*R@|3$
for(int i=0;i<nStartPos.length;i++) ?gS~9jgcd
{ `~LaiN.
// output.writeLong(nPos); Mey=%Fv
output.writeLong(fileSplitterFetch.nStartPos); , ins/-3
output.writeLong(fileSplitterFetch.nEndPos); h8HA^><Xr
} M_\)<a(8
output.close(); Xyw;Nh!!d
} )(`,!s,8)
catch(IOException e){e.printStackTrace ();} T2k# "zD
catch(Exception e){e.printStackTrace ();} !^w}Sp
} }vQY+O
R<ZyP~
HuajdC~
//读取保存的下载信息（文件指针位置） yzJTNLff
private void read_nPos() :UDe\zcd"
{ *l'5z)]
try{ )H<F([Jri
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y;tX`5(fe
int nCount = input.readInt(); A<cnIUW
nStartPos = new long[nCount]; m[&pR2T
nEndPos = new long[nCount]; y-vBC3
for(int i=0;i<nStartPos.length;i++) ,in"8aT}~
{ =bb)B(
nStartPos = input.readLong(); Fx@@.O6
nEndPos = input.readLong(); .4,l0Nn`W
} S d]`)
input.close(); }U$p[Gi<
} (s!cd]Qa.
catch(IOException e){e.printStackTrace ();} B6]M\4v
catch(Exception e){e.printStackTrace ();} y3mJO[U0 a
} uJ%XF*>_D
oz\r0:
%;YERO!
private void processErrorCode(int nErrorCode) @4j!M1}4
{ :JG2xtn
System.err.println("Error Code : " + nErrorCode); YDiru
} hkR Jqta)
SWMi+)
qISzn04
//停止文件下载 M\bea
public void siteStop() 8f-B-e?k
{ YN5p@b=FX
bStop = true; __,}/|K2
for(int i=0;i<nStartPos.length;i++) @m ?&7{y#?
fileSplitterFetch.splitterStop(); -wn(J5NnR
Xq.GvZS`
!8OUH6{2
} YX6[m6LU
} yI}_ U
//负责部分文件的抓取 +L<x0-&
**FileSplitterFetch.java u[1'Ap
*/ FLOSdMYdw
package NetFox; T~-PT39E
W8s/"
h%(0|
import java.io.*; (Qz| N
import java.net.*; %z AN@
.5?Md
tU(vt0~b
public class FileSplitterFetch extends Thread { "(SZ;y
|>AHc_:$$
e(sV4Z~
String sURL; //File URL ;PG,0R`Z;
long nStartPos; //File Snippet Start Position xouy|Nn'
long nEndPos; //File Snippet End Position <LOas$
int nThreadID; //Thread's ID 9/R<,
boolean bDownOver = false; //Downing is over ]iVoF N}^
boolean bStop = false; //Stop identical Rac4a@hZ
FileAccessI fileAccessI = null; //File Access interface # >L^W7^
*heX[D &>)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D}:M0EBS
{ nV+]jQ~o
this.sURL = sURL; dnUiNs8
this.nStartPos = nStart; d(j|8/tpA
this.nEndPos = nEnd; 9mfP9
nThreadID = id; {w|KWGk2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N"#=Q=)x
} 9W@Tf
Fwv(J_'q
dEM=U;
public void run() iWu^m+"k
{ rJ}k!}G
while(nStartPos < nEndPos && !bStop) '9#h^.
{ MnymV;y"
:6X?EbXhK
Sej\Gt
try{ E;C=V2#>[
URL url = new URL(sURL); /J0ctJ2k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fl&Z}&5p
httpConnection.setRequestProperty("User-Agent","NetFox"); 6N.+
String sProperty = "bytes="+nStartPos+"-"; ti^msC8e
httpConnection.setRequestProperty("RANGE",sProperty); \LZVazXD
Utility.log(sProperty); - d(RK_
.|9o`mF7
!]z6?kUK
InputStream input = httpConnection.getInputStream(); S`?cs^?
//logResponseHead(httpConnection); gw);b)&mx
9Wi+7_)
jFMf=u&U
byte[] b = new byte[1024]; G Za<
int nRead; Y>: e4Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p[M*<==4
{ F),wj8#~>-
nStartPos += fileAccessI.write(b,0,nRead); ON/U0V:v
//if(nThreadID == 1) rq>OmMQ67
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |=9=a@l]P
} ^%r>f@h!L
=jN9PzLk
}c~o3t(7`b
Utility.log("Thread " + nThreadID + " is over!"); b];? tP
bDownOver = true; F/I`EV
//nPos = fileAccessI.write (b,0,nRead); B'"RKs]
} 5Myp#!|x:
catch(Exception e){e.printStackTrace ();} 8h| 9;%
} O'} %Bjl
} C7lBK<gQ
%;{Ro)03
A#P]|i
//打印回应的头信息 17{$D,P
public void logResponseHead(HttpURLConnection con) 4(FEfde=
{ jvfQG:F }
for(int i=1;;i++) 4S+sz?W2j
{ ,>Lj>g{~
String header=con.getHeaderFieldKey(i); RRH[$jk
if(header!=null) 9!06R-h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @on\@~Ug
Utility.log(header+" : "+con.getHeaderField(header)); nY[]k p@
else XLNR%)l
break; k^Q>
} 4]$$ar)
} iCrLZ"$M
?H2{R:
h (1 }g/
public void splitterStop() 1-M\K^F
{ \P` mV9P
bStop = true; aV'r oxM
} 2PSt*(
6#rj3^]
j >wT-s
} `K^j:fE7n
wpLC,
)m7 Yo
/* U1wsCH3+n
**FileAccess.java *3>$f.QU
*//文件访问(定位，写) Q7b$j\;I
package NetFox; &7CAxU;i3
import java.io.*; wUbs9y<
O$Z<R:vVA
8={"j
public class FileAccessI implements Serializable{ 7CKh?>
m"CsJ'\ors
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4pfv?!Oj
RandomAccessFile oSavedFile; 5@xl/
long nPos; ;%H/^b.c
@a{1vT9b
|tkhsQ-;
public FileAccessI() throws IOException *j0kb"#
{ LYv$U;*+
this("",0); hD5G\TR.
} mSu1/?PS
rcWr0q
Jm l4EW7
public FileAccessI(String sName,long nPos) throws IOException (\=iKE4#
{ OYsG#
oSavedFile = new RandomAccessFile(sName,"rw"); v)a$;P%
this.nPos = nPos; },G>+ s8h
oSavedFile.seek(nPos); ;ESuj'*t
} C=z7Gk=
X_0Ta_u?T
UmRI! WQl
public synchronized int write(byte[] b,int nStart,int nLen) +%hA6n
{ U[Pll~m2b
int n = -1; C {GSf`D!T
try{ -`o22G3w
oSavedFile.write(b,nStart,nLen); pg%'_+$~m
n = nLen; 7fg +WZ
} 8 )w75+&
catch(IOException e) \!["U`\.K
{ G/*0*&fW
e.printStackTrace (); oq<n5
} &Jr~)o
`2M`;$~ 5
J,bE[52
return n; 9ntXLWK7e
} 3 oG5E"G
-R[ *S "
(\QkXrK
} 0m|$ vb
'NJCU.lKm
5+gSpg]i
/* YRy5.F%?
**SiteInfoBean.java $RYsqX\v
*/ 1Ue;hu'q:
package NetFox; V*m@Rs!)2
G@O~*k1v
<L1;aNN
public class SiteInfoBean { 0pSqk/
nbpGxUF`]
].j;d2xT\
private String sSiteURL; //Site's URL m&H@f:
private String sFilePath; //Saved File's Path #sOkD
private String sFileName; //Saved File's Name Kug_0+gI
private int nSplitter; //Count of Splited Downloading File 86s.qPB0
o0nKgq'w|x
J8T?=%?=
public SiteInfoBean() EMDsi2
{//nSplitter的缺省值为5 /idQfff
//default value of nSplitter is 5 ="$9 <wt
this("","","",5); 2\Vzfca
} }K!)Z}8
b-1cA1#_cP
!NNq(t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dJZMzn
{ J~6-}z
sSiteURL= sURL; >&|C E2'
sFilePath = sPath; _7AR2
sFileName = sName; MVGznf?
this.nSplitter = nSpiltter; 5/:BtlFx
VPB,8zb]
bN6FhKg|
} F9sVMV
+[MzF EE[
<mm.b
public String getSSiteURL() ^MyuD?va
{ M>pcG.6V
return sSiteURL; !);kjXQS?
} ]vJ] i<|b
J!$q"0G'WT
,~@Nhd~k
public void setSSiteURL(String value) 5$,dpLbL
{ R89;<,Ie
sSiteURL = value; >i>%@
} rpk )i:k\
U{2[nF
~>af"<
public String getSFilePath() _]~gp.
{ NArql
return sFilePath; %"2;i@
} : GZx-
?N 6'*2{NT
d66 GO];"
public void setSFilePath(String value) 73kF=*m
{ <p<J;@
sFilePath = value; |fx*F}1
} 'n7)()"2
cr{;gP
+ht -Bl
public String getSFileName() <<zYF.9L]
{ KaJCfu yp
return sFileName; w`kn!k8
} e12.suv
_H:mBk,,
zj ;'0Zu
public void setSFileName(String value) Y<'T;@
{ 6!|-,t><
sFileName = value; 2]Nc@wX`p
} : Gp,d*M
f$G{7%9*
jl;%?bx
public int getNSplitter() iRo/~(
{ ""GeO%J8
return nSplitter; Jww LAQ5
} !TJCQ[Aa}
1LbJR'}
T)"B35
public void setNSplitter(int nCount) n+db#qAj5
{ lKo07s6u
nSplitter = nCount; z\zmAus
} vJ__jO"Sq
} qVOlUH
_raj b1!
`K.2&6xc
/* 0B0Uay'd_
**Utility.java lx8@;9fLy
*/ UenB4
package NetFox; O7p>"Bh
p`@7hf|hm
[b-wak})aD
public class Utility { >[]@Df,p
l$ABOtM@
K5O8G
public Utility() |Co ?uv i
{ {5tb.{
7!0~sf9A
g5gq{KlU
} iXp*G52
yQA6w%
//线程睡眠 |/u&%w?W
public static void sleep(int nSecond) Byx8`Cx1
{ &,pL3Qos
try{ KLpe!8tAe
Thread.sleep(nSecond); Xx~za{p
} FOB9J.w4
catch(Exception e) D$W&6'
{ (Sr D
e.printStackTrace (); D -Goi-4
} !,f{I5/
} P&Vqr
:x*|?zII
//日志 C?v_ig
public static void log(String sMsg) [<;4$}f\
{ 6xk~Bt
System.err.println(sMsg); v7?sXW
} Pqe{C?7B
xh$1Rwa
FdR!jt
public static void log(int sMsg) \ W3\P=
{ gxry?':
System.err.println(sMsg); biTET|U`$
} BU-m\Kf)
} ^oNk}:>
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6%/@b`vZ
/* OR4ZjogzY
**TestMethod.java Q{hXP*5
*/ 1bW[RK;GE
package NetFox; \`:X37n)0q
2&st/y(hs
%#!pAUP\&
public class TestMethod { F9DY\EI
>'>onAIL
8cqH0{
public TestMethod() 3l?D%E]P
{ ///xx/weblogic60b2_win.exe 7Sc._G{[%
try{ Lq#>N_72W0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g<,kV(_7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [yzDa:%
SiteFileFetch fileFetch = new SiteFileFetch(bean); T~shJ0%
fileFetch.start(); ~&>|u5C*@
} Rj&V~or
catch(Exception e){e.printStackTrace ();} g. V6:>,
)sWC5\
yH\z+A|
} E^uWlUb{
7M~w05tPh
+}IOTw"O`
public static void main(String[] args) }yde9b?F
{ >heFdKq1
new TestMethod(); a<-'4D/
} rFY% fo
} oLJP@J
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