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)); ZCbnDj
} ,y57tY
for(int i=0;i<nEndPos.length-1;i++) =7U_ jDME
{ D!oELZ3
nEndPos = nStartPos[i+1]; kr|u ||
} Uxyj\p
nEndPos[nEndPos.length-1] = nFileLength; f2y:K6$'l*
} "/zIsn7
} PnKgUJoa0
e5 ?;{H
wA#w]8SM
//启动子线程 m%bw$hr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R}-<ZJe
for(int i=0;i<nStartPos.length;i++) XOe8(cXa9
{ 2/c^3[ccR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C&QT-|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1eZ759PoO
nStartPos,nEndPos,i); u,R;=DNl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n^Uu6
fileSplitterFetch.start(); h8Bs=T
} ;L gxL Qy;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Deg!f\g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |aT&rpt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VNmQ'EuV}2
nEndPos = " + nFileLength); &ZRriqsQg
// fileSplitterFetch[nPos.length-1].start(); ,y+}0q-Ou
R4V~+tnbG&
;ss,x
//等待子线程结束 K6=i\
//int count = 0; Vu/{Hr
//是否结束while循环 8~=<!(M)m/
boolean breakWhile = false; P)2.Gx/
o-))R| ~z
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while(!bStop) FSs<A@
{ l1&NU'WW
write_nPos(); S<f]Y4A&
Utility.sleep(500); W]]@pbG"H\
breakWhile = true; W?n)IBj8
'9+JaB
9Dq^x&z(
for(int i=0;i<nStartPos.length;i++) Gd:TM]rJ
{ 7Z#r9Vr
if(!fileSplitterFetch.bDownOver) xb2xl.2x!
{ fq@r6\TI
breakWhile = false; (^:0g.~c
break; }-ly'4=l
} BP&T|s
} XA&Vtgu
if(breakWhile) (V:z7
break; s\)0f_I
']N1OVw^vf
Y;X_E7U
//count++; 00?_10x)
//if(count>4) 0%Y8M` ~s7
// siteStop(); H+ P&} 3
} PJ-EQ6W
)(?,1>k`Z
,G q?
System.err.println("文件下载结束！"); ^ZxT0oaL
} qT<OiIMj^
catch(Exception e){e.printStackTrace ();} 78=a^gRB
} 4jOq.j
^V1.Y
9hJlc
//获得文件长度 @O!BQ^'hk#
public long getFileSize() |XDbf3^6
{ +b =X~>vZ
int nFileLength = -1; Y$vobi$
try{ P}2i[m.*,
URL url = new URL(siteInfoBean.getSSiteURL()); I%^Bl:M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \jkMnS6FvL
httpConnection.setRequestProperty("User-Agent","NetFox"); -`I&hzl6E
:i?7RouO
~`xaBz0q
int responseCode=httpConnection.getResponseCode(); >/r^l)`9_f
if(responseCode>=400) cYC@@?
{ XF6ed
processErrorCode(responseCode); !-cO0c!
return -2; //-2 represent access is error c'wxCqnE
} 8|z@"b l)
g< F7UA
^$N}[1
String sHeader; 0r=KY@D
#FZoi:'Q
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for(int i=1;;i++) lpy(un
{ j3Sz+kOf,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hxB` hu-
//Utility.log(in.readLine()); PnUYL.v
sHeader=httpConnection.getHeaderFieldKey(i); F['<;}
if(sHeader!=null) mRECdGst
{ ]8m_+:`=
if(sHeader.equals("Content-Length")) 3axbWf3[
{ 8mmHefZ}2!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pX/42W
break; Ft[)m#Dj`
} mj7Em&
} :L6,=#
else gG,"wzj
break; U2DE zr
} k"L?("~
} !eC]=PoY
catch(IOException e){e.printStackTrace ();} M>yt\qbkA
catch(Exception e){e.printStackTrace ();} Fv )H;1V
s|O4>LsG
< %t$0'
Utility.log(nFileLength); @hG]Gs[,o
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ju8DmC5
return nFileLength; ds#om2)
} VQV%1f
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*}Cm/li/w
//保存下载信息（文件指针位置） R#\o*Ta
private void write_nPos() u&npUw^Va
{ UWPzRk#s"
try{ k0e {c
output = new DataOutputStream(new FileOutputStream(tmpFile)); M,R**z
output.writeInt(nStartPos.length); :W6R]y
for(int i=0;i<nStartPos.length;i++) }Y=X{3+~.
{ =9;2(<A
// output.writeLong(nPos); Q$B\)9`v[
output.writeLong(fileSplitterFetch.nStartPos); "c2{n,
output.writeLong(fileSplitterFetch.nEndPos); q(nPI
} .}4^b\
output.close(); "/~KB~bB
} Q\qI+F2?
catch(IOException e){e.printStackTrace ();} xfFsW^w
catch(Exception e){e.printStackTrace ();} so]p1@K
} Lt?k$U{qe)
ebTwU]Nb
d+iV19#i
//读取保存的下载信息（文件指针位置） }[O/u <Z
private void read_nPos() f8vWN
{ SbX#$; ks~
try{ KM&bu='L^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :vWixgLg
int nCount = input.readInt(); 8n~ o="
nStartPos = new long[nCount]; FC&841F
nEndPos = new long[nCount]; kWm[Lt
for(int i=0;i<nStartPos.length;i++) s<b(@L 1
{ dZ;rn!dg>
nStartPos = input.readLong(); g5>c-i
nEndPos = input.readLong(); &3~_9+
} MWHzrqCA
input.close(); _uQxrB"9
} #}8 x
catch(IOException e){e.printStackTrace ();} h#?)H7ft
catch(Exception e){e.printStackTrace ();} X6SqOb\(a
} E!]d?t3b
o7^u@*"F
Q?WgGE4>
private void processErrorCode(int nErrorCode) ^sb+|b
{ f`Wces=5
System.err.println("Error Code : " + nErrorCode); b[;Zl<
} K!A;C#b!
227 Z6#CF!
96P3B}Dk
//停止文件下载 bQBYzvd
public void siteStop() |*te69RX
{ _a&Mk
bStop = true; A"pV 7 y
for(int i=0;i<nStartPos.length;i++) sA1 XtO<&7
fileSplitterFetch.splitterStop(); NU |vtD
whb,2=gIE
dePI&z:
} RAY.]:}jr
} Hr/3nq}.
//负责部分文件的抓取 0{Bhr12V
**FileSplitterFetch.java ^h~oxZJw
*/ z>9gt
package NetFox; ;UoXj+Z
GkYD:o=qx
wfY]J0l
import java.io.*; T*v@hbJ
import java.net.*; Zrm!,qs
_^Yav.A=
@$] CC1Y
public class FileSplitterFetch extends Thread { 5l,Q=V^@l
6"PwOEt
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String sURL; //File URL K.I\E
long nStartPos; //File Snippet Start Position "u.4@^+i
long nEndPos; //File Snippet End Position jSMs<ox
int nThreadID; //Thread's ID Qe;j_ BH
boolean bDownOver = false; //Downing is over :^*9Eb
boolean bStop = false; //Stop identical ," ~4l&
FileAccessI fileAccessI = null; //File Access interface EWn\]f|
gW_^GrKpI
I$vM )+v=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T*irCe
{ ]id5jVY
this.sURL = sURL; x"xtILrI
this.nStartPos = nStart; 8"2X 8C8
this.nEndPos = nEnd; .X(*mmH
nThreadID = id; E])X$:P?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F2k)hG*|{
} +'f38D*
53jtwklA
B}A7Usm
public void run() 8jxs%N,aI
{ ;zZGV4Qc~
while(nStartPos < nEndPos && !bStop) p@x1B &Z
{ f7Fr%*cO
;.wWw" )
}iF"&b0n"
try{ {Kh u'c
URL url = new URL(sURL); w+Cs=!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2 - ?
httpConnection.setRequestProperty("User-Agent","NetFox"); \JX.)&> -
String sProperty = "bytes="+nStartPos+"-"; c7$U0JO
httpConnection.setRequestProperty("RANGE",sProperty); U3zwC5}BN
Utility.log(sProperty); $xU5vCwAo
%}%vey
cr_Q,*
InputStream input = httpConnection.getInputStream(); V6{P41_
//logResponseHead(httpConnection); C)Ez>~Z
3"OD"
ZZXQCP6]
byte[] b = new byte[1024]; Gj}P6V_
int nRead; ctg[C$<q|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _a3,Zuv
{ L>qLl_.
nStartPos += fileAccessI.write(b,0,nRead); ;v?!Pml2k
//if(nThreadID == 1) ua-cX3E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8}0O @ wq
} Vgh_F8G!V
s)~60c
!pNY`sw}
Utility.log("Thread " + nThreadID + " is over!"); 5YG?m{hyn_
bDownOver = true; C$1}c[
//nPos = fileAccessI.write (b,0,nRead); qq+fUfB2:
} 4Fr\=TX
catch(Exception e){e.printStackTrace ();} ;&Oma`Ec
} nD$CY K
} e Ert_@}
}"'^.FG^_
IaU
//打印回应的头信息 |W/_S^C
public void logResponseHead(HttpURLConnection con) 6J|Y+Y$
{ wM;9plYlw0
for(int i=1;;i++) 1o;+.]B
{ [V5ebj:6w
String header=con.getHeaderFieldKey(i); JRm:hf'
if(header!=null) H?P:;1A]c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hoc$aqP6pp
Utility.log(header+" : "+con.getHeaderField(header)); Z5uetS^
else Q`Q%;%t
break; eoS8e$}
} A(mU,^
} Ew=8"V`C
_d'x6$Jg
\S)\~>.`y!
public void splitterStop() B?nQUIb:
{ i'5Q.uX
bStop = true; iR9 $E
} pr8eRV!x
zUM;Qwl
2z7+@!w/
} cp0@wC#d
,OX(z=i_
:t6w+h
/* Hb KJ&^
**FileAccess.java X=Q)R1~6v
*//文件访问(定位，写) }jM&GH1
package NetFox; VfJYYR
import java.io.*; $&96qsr
8I)66
ysV0Ed
public class FileAccessI implements Serializable{ ,%#FK|
L\Uf+d:&}G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bu[v[U4
RandomAccessFile oSavedFile; [2UjY^\;T
long nPos; TKpka]nJ
C`z[25o
y#5xS
public FileAccessI() throws IOException ty|E[Ez1
{ bwG2=
this("",0); %nQii?1`i
} I @TR|
CA)DQYp{
QAigbSn]
public FileAccessI(String sName,long nPos) throws IOException wfQ6J0
{ _ji"##K
oSavedFile = new RandomAccessFile(sName,"rw"); Amf gc>eJ
this.nPos = nPos; EELS-qA
oSavedFile.seek(nPos); { as#lHn
} V?Y;.n&y
n0_q-8r
=7@N'xX
public synchronized int write(byte[] b,int nStart,int nLen) )<bgZ, v
{ 5t`< KRz)I
int n = -1; n=#AH;42
try{ ufE;rcYE
oSavedFile.write(b,nStart,nLen); )$XW~oA'
n = nLen; M=$ qus
} iB;EV8E
catch(IOException e) fmf3Hp@
{ ;uj&j1
e.printStackTrace (); .}n%gc~A
} ;/w-7O:
#~l(t_m{
j^#4!Ue
return n; DD`Bl1)
} T 22tZp
yOwo(+ 2
*Y"Kbn6
} :ulOG{z
h.PVRAwk
o!W 71
/* (jbHV.]P9
**SiteInfoBean.java fYrC;&n
*/ F?#^wm5TZ
package NetFox; .{[+d3+,
-FRMal4Pg0
npC:SrI%
public class SiteInfoBean { eT33&:n4
8aDhHXI
1h uU7xuf
private String sSiteURL; //Site's URL W^{zlg
private String sFilePath; //Saved File's Path Fk(nf9M%
private String sFileName; //Saved File's Name {j$:9 H
private int nSplitter; //Count of Splited Downloading File `@%hz%8Y
84g$V}mp
= F*SAz
public SiteInfoBean() DFDlp
{//nSplitter的缺省值为5 m'{gO9V
//default value of nSplitter is 5 m)"gj**|y
this("","","",5); bMe/jQuL.$
} :;Z?2P5i
+9LIpU&5
qiEw[3Za]'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .V~z6
{ uG-t)pej
sSiteURL= sURL; UnTnc6Bo7W
sFilePath = sPath; F|mppY'<J
sFileName = sName; BwpEIV@b]
this.nSplitter = nSpiltter; gY!+x=cx0
u={A4A#
:g&9v_}&K{
} imb.CYS74
Fpe>|"&
K qK?w*Qw
public String getSSiteURL() ]#$l"ss,
{ KZeaM
return sSiteURL; PB[Y^q
} Sq<ds}o'8l
O4`am:@
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public void setSSiteURL(String value) DIAHIV<
{ LVHIQ9
sSiteURL = value; E4}MU}C#[
} Gl am(V1
ZMp5d4y5
{$ a $m
public String getSFilePath() d2\#Zlu<
{ @wVq%GG}
return sFilePath; _;zIH5 H
} 6h5DvSO
n]nb+_-97
ve3-GWT{C
public void setSFilePath(String value) i!yu%>:M
{ w'i8yl bZ
sFilePath = value; {7F?30: ]
} rjaG{ i
itU P%
%DQ!#Nl*
public String getSFileName() @Z+(J:Grm5
{ z5tOsU
return sFileName; ]=ubl!0=:
} pw, <0UhV
A_pcv7=@
a_V.mu6h6p
public void setSFileName(String value) fkHCfcU
{ }LA7ku
sFileName = value; Id}@
} RCC~#bb
+M s`C)f
m[w 8|[
public int getNSplitter() &sA@!
{ LX%UkfA9
return nSplitter; P`$Y73L
} CqAv^n7 }
h*lU&8)m\
0}4FwcCr\
public void setNSplitter(int nCount) ]"X} FU
{ =5kTzH.
nSplitter = nCount; _mG>^QI.
} 5^0K5R6GQf
} IEj=pI
3:B4;
w+Oo-AGNH
/* X"fSM #
**Utility.java R=m9[TgBm
*/ U#gv ~)\k
package NetFox; cERmCe|/CG
z$]HZ#aRE
&{=`g+4n
public class Utility { .!2Ac
m2r%m y
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public Utility() @7z_f!'u
{ ~'u %66
4+2hj*I
=5D@~?W ZG
} LQ'VhNU
fs3jPHZJ#
//线程睡眠 ;Y@"!\t}
public static void sleep(int nSecond) Ynx.$$`$=
{ a";xG,U
try{ a"pejW`m
Thread.sleep(nSecond); $8t\|O3
} yq,%ey8
catch(Exception e) kFZjMchm A
{ f<K7m
e.printStackTrace (); nv-_\M
} M\w%c5
} ?6>rQ6tBv
%>)&QZig/
//日志 (Gp|K6
public static void log(String sMsg) 1z5\>F
{ N^U<;O?YDW
System.err.println(sMsg); FK!UUy;
} i#1~<U
JzZ9ua
t1%<l
public static void log(int sMsg) u4,b%h.
{ vo3[)BDbT
System.err.println(sMsg); }RPeAcbU_
} J6m(\o
} uom~,k$|
.|Bmg6g*
wG2-,\:
/* AYLCdCoK.
**TestMethod.java QnPgp(d<
*/ @[] A&)B
package NetFox; GP._C=]?c
'RjMwJy{
M!E#T-)
public class TestMethod { eVx &S a
Uk0]A
;th]/ G
public TestMethod() x[i Et%_
{ ///xx/weblogic60b2_win.exe xB&6f")
try{ -ipfGb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zcTY"w\b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W=)wiRQm
SiteFileFetch fileFetch = new SiteFileFetch(bean); <(<19t5.
fileFetch.start(); *E-VS= #
} FeM,$&G:
catch(Exception e){e.printStackTrace ();} %=O$@.%Zc
xK8R![x
1>1ii
} _Mis-K:]{?
;"@FLq(n
!agtgS$qII
public static void main(String[] args) !Ho=(6V
{ /Vy8%
new TestMethod(); VSI.c`=,
} ErDt~FH
} P=jbr"5Q:
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