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)); I6,sN9` K
} 5,1q%
for(int i=0;i<nEndPos.length-1;i++) @dp1bkU
{ {glRXR
nEndPos = nStartPos[i+1]; &+>)H$5
} _I}rQfPJ
nEndPos[nEndPos.length-1] = nFileLength; xtP=/B/
} 5Pu F]5
} hg=BXe4:
1O]27"9
6 w:@i_2^
//启动子线程 jt8% L[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *,=WaODO%
for(int i=0;i<nStartPos.length;i++) ~'2im[f J
{ Nd.Tda!Kg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9XPQ1LSx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !%_H1jk
nStartPos,nEndPos,i); ua!g}m~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h2C1'+Q{9
fileSplitterFetch.start(); IfGQeynj
} .+TriPL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9QryW\6.@z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sk 10"DB/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z/@%MEU[zl
nEndPos = " + nFileLength); (" +/ :
// fileSplitterFetch[nPos.length-1].start(); Ood'kAH1B
]kd )j
OY/sCx+c
//等待子线程结束 L?5OWVX!v
//int count = 0; >f*[U/{ K
//是否结束while循环 a>{b'X^LV
boolean breakWhile = false; |.zotEh
HN*w(bROr
'hM?J*m
while(!bStop) ^"d!(npw
{ ^v].mV/
write_nPos(); JV#)?/a$z
Utility.sleep(500); H21\6 GY
breakWhile = true; jW-j+WGSM
(SlrV8;
gB?~!J?
for(int i=0;i<nStartPos.length;i++) &G>EBKn\2`
{ @#%rTKD9F
if(!fileSplitterFetch.bDownOver) d#9"_{P
{ y`EcBf
breakWhile = false; a+CHrnU\;
break; $*{$90Q
} buhn~ c
} F"-w
if(breakWhile) $LF
break; Bjz\L0d
K"sfN~@rT[
KR6*)?c`
//count++; hC.7Z]
//if(count>4) <E|K<}W#
// siteStop(); bTn7$EG
} 43;@m}|7$
_r}oYs%1
@:~O
System.err.println("文件下载结束！"); f*g>~!
} kxg]sr"
catch(Exception e){e.printStackTrace ();} '`Smg3T!~S
} nJ|8#U7
#(53YoV_8
"kKIVlC
//获得文件长度 6SMGXy*]^
public long getFileSize() VT\o=3_
{ o4b!U%
int nFileLength = -1; ogX'3L
try{ Oifu ?f<r
URL url = new URL(siteInfoBean.getSSiteURL()); X"W%(x`w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PomX@N}1
httpConnection.setRequestProperty("User-Agent","NetFox"); 6?0^U 9
22|f!la8n
~7!J/LHg
int responseCode=httpConnection.getResponseCode(); %3i/PIN
if(responseCode>=400) .6[xX?i^T
{ g]V}azLr
processErrorCode(responseCode); 1@Bq-2OD4
return -2; //-2 represent access is error j}chU'if
} W&]grG2/
Z3G>DF:$
PiZt?r?5w|
String sHeader; -0Q:0wU
0:**uion
:XMw="u=
for(int i=1;;i++) hltH{4
{ Lrz>0_Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .BXZ\r`
//Utility.log(in.readLine()); ctOC.
sHeader=httpConnection.getHeaderFieldKey(i); !UD62yw~
if(sHeader!=null) zVs_|x="
{ P sD+?
if(sHeader.equals("Content-Length")) )@3ce'
{ QJo)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }(-R`.e;
break; #Xri%&~
} ke~O+]
} jz|zq\Eek
else \qAMs^1-
break; y'Xg"
} O!zH5
} e+=Ojo#
catch(IOException e){e.printStackTrace ();} kRskeMr:Rd
catch(Exception e){e.printStackTrace ();} ~\K+)(\SNp
"gdmRE{x
ASAz<H$
Utility.log(nFileLength); d'Z|+lq:
Q/iaxY#
mqk~Pno|<
return nFileLength; b^PYA_k-Xn
} (@O F Wc"p
Y.@ vdW
l_u1 ~K
//保存下载信息（文件指针位置） |nXs'TO'O
private void write_nPos() _"J-P={=
{ mY.[AIB
try{ sRo%=7Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); r,i^-jv;
output.writeInt(nStartPos.length); tCK%vd%
for(int i=0;i<nStartPos.length;i++) W)V"QrFK
{ pr/yDGia
// output.writeLong(nPos); Iq_cs '
output.writeLong(fileSplitterFetch.nStartPos); $dci?7q
output.writeLong(fileSplitterFetch.nEndPos); #:{PAt
} B{QY-F~
output.close(); E/LR(d_
} hH{&k>
catch(IOException e){e.printStackTrace ();} v%V$@MF
catch(Exception e){e.printStackTrace ();} /bVU^vo
} +"T?.,
G F,/<R#
G[6V=G
//读取保存的下载信息（文件指针位置） ?`,UW;Br6
private void read_nPos() 52K3N^RgR
{ 6ndt1W z
try{ >t?;*K\x"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); " 9 h]P^
int nCount = input.readInt(); (C,PGjd
nStartPos = new long[nCount]; V?HC\F-
nEndPos = new long[nCount]; O} QTg
for(int i=0;i<nStartPos.length;i++) 2M= gpy
{ ,/|"0$p2x
nStartPos = input.readLong(); j*g5f
nEndPos = input.readLong(); WU{G_Fqaz
} sBq @W4
input.close(); {k}S!T
} <"AP&J'H
catch(IOException e){e.printStackTrace ();} J^ryUOo}b
catch(Exception e){e.printStackTrace ();} 4'?kyTO~
} (<(8(}x
qWtvo';3
5>"$95D
private void processErrorCode(int nErrorCode) xgL*O>l)
{ @1gX>!
System.err.println("Error Code : " + nErrorCode); U9IN#;W
} Gu|}ax"
yFshV\
1'R]An BV
//停止文件下载 tH2y:o72
public void siteStop() e[yk'E
{ X|7gj&1
bStop = true; ]U! ?{~
for(int i=0;i<nStartPos.length;i++) QgC
fileSplitterFetch.splitterStop(); jw5Bbyk
W<xu*U(A
%[-D&flKC
} Sh*LD QL<?
} =5oE|F%
//负责部分文件的抓取 ,S2D/Y^>
**FileSplitterFetch.java y!."FoQ
*/ %rzC+=*;
package NetFox; :U0z;
eFp4MD8?
B~V^?."
import java.io.*; 41^+T<+
import java.net.*; /^i7^
ON~SZa
~0!s5
public class FileSplitterFetch extends Thread { bB->\
TV#pUQ3K
O2q`2L~
String sURL; //File URL F# y5T3(P
long nStartPos; //File Snippet Start Position hoD (G X
long nEndPos; //File Snippet End Position ZTVX5"#Q
int nThreadID; //Thread's ID a"0Xam
boolean bDownOver = false; //Downing is over S j)&!
boolean bStop = false; //Stop identical 0j7W\'!t
FileAccessI fileAccessI = null; //File Access interface BYyR-m
p./zW )7+
s6lo11
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EQ-r
{ T' %TMA
this.sURL = sURL; |#LU"D
this.nStartPos = nStart; vtKQvQ
this.nEndPos = nEnd; `-"2(Gp
nThreadID = id; _)yn6M'Dt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vXAO#'4tm%
} 6UG7lH!M
=66dxU?}
'0[D-jEr
public void run() 0hnN>?
{ !=3[Bm G
while(nStartPos < nEndPos && !bStop) !<Ma9%uC{
{ 2)Grl;T]s
uwXquOw
TIbiw
try{ t4/d1qW0
URL url = new URL(sURL); #;)Oi9{9;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (y[+s?;WyB
httpConnection.setRequestProperty("User-Agent","NetFox"); 4`yCvPu
String sProperty = "bytes="+nStartPos+"-"; ztKmB
httpConnection.setRequestProperty("RANGE",sProperty); [ma'11?G
Utility.log(sProperty); WolkW:(Cg
L%}k.)yev
zXx HaM
InputStream input = httpConnection.getInputStream(); )pJ} $[6
//logResponseHead(httpConnection); y>_lxLhmO#
+)h*)
__fa,kK{?
byte[] b = new byte[1024]; )q8w+'z
int nRead; JcL4q\g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :3pJGMv(
{ V##=-KZ
nStartPos += fileAccessI.write(b,0,nRead); {Iy<iV
//if(nThreadID == 1) xeF0^p7Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c Owa^;
} RSC^R}a5
<^c?M[j
y[:\kI
Utility.log("Thread " + nThreadID + " is over!"); 9=O`?$y
bDownOver = true; l=ehoyER
//nPos = fileAccessI.write (b,0,nRead); ~[l6;bn
} fb3(9
catch(Exception e){e.printStackTrace ();} 4{=zO(>
} l\xcR]O
} hOw
S.pL^Ru
Q1yMI8
//打印回应的头信息 AE?MEag
public void logResponseHead(HttpURLConnection con) 2#1"(m{
{ AiKja>Fl<
for(int i=1;;i++) 4r&DW'
{ e&sZ]{uD
String header=con.getHeaderFieldKey(i); :,Z'/e0&
if(header!=null) >-J%=P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _;L%? -2c
Utility.log(header+" : "+con.getHeaderField(header)); `2-6Qv
else +z}O*,M"q
break; *(wkgn
} `Sgj!/!F
} "Zm**h.t
& mwQj<Z
d5Hp&tm
public void splitterStop() +a1Or
{ H3\4&q
bStop = true; nwuH:6~"
} eB%hP9=:x
XrP'FLY o
8T<LNC
} ;w>Dqem
vP6NIcWC3
t|-TG\Q X
/* (K9pr>le
**FileAccess.java \OPJ*/U
*//文件访问(定位，写) x-27rGN
package NetFox; &O8vI,M
import java.io.*; riw0w
7q\&
H4RqOI
public class FileAccessI implements Serializable{ &U*MLf83`
a7$-gW"Z(,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (zbV-4C
RandomAccessFile oSavedFile; BNi6I\wa
long nPos; 7Z%EXDm4/c
pRR1k?
m8M2ka
public FileAccessI() throws IOException =VIU
{ stGk*\>U'
this("",0); %!DdjC&5*
} Ac^hZ.qPz
N;Hoi8W
>A&D/kMO
public FileAccessI(String sName,long nPos) throws IOException @}9*rWJIE
{ 3DjlX*
oSavedFile = new RandomAccessFile(sName,"rw"); WxPu{N
this.nPos = nPos; *^[m?3"W
oSavedFile.seek(nPos); @yV.Yx"p_
} gn82_
)R %>g-dw
10tlD<eYb
public synchronized int write(byte[] b,int nStart,int nLen) 7x>\/l(
{ #/N;ScyUJT
int n = -1; t =LIkwD
try{ !s^[|2D_U
oSavedFile.write(b,nStart,nLen); &<nj~BL
n = nLen; -Cn x!g}
} up_Qv#`Q
catch(IOException e) +"}#4
{ B`{7-Asc1
e.printStackTrace (); #su R[K*S
} \B/!}Tn;
.)(5F45Wg
(1%O;D.*?{
return n; N>V\
} Q*jNJ^IW
`@<>"ff#F
y@XE! L
} M{GT$Q
]g] ]\hS
}BYs.$7
/* . E8Gj'yO
**SiteInfoBean.java DXF>#2E^+
*/ My6a.Kl
package NetFox; .gQYN2#zb
aU\R!Y$/"
f]sc[_n]
public class SiteInfoBean { t,w'w_C
bU$f4J
e^=b#!}-5:
private String sSiteURL; //Site's URL =|+%^)E
private String sFilePath; //Saved File's Path KP@bz
private String sFileName; //Saved File's Name \d)HwO
private int nSplitter; //Count of Splited Downloading File R6cd;| fan
x@*RF:\}
;9MIapfUd(
public SiteInfoBean() Sdzl[K/}
{//nSplitter的缺省值为5 0{^ 0>H0
//default value of nSplitter is 5 qtR/K=^i
this("","","",5); )U|0vr8:
} [AHoTlPZ
R4_BP5+
dDrzO*a\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q<XleC
{ fK/|0@B8
sSiteURL= sURL; >,6%Y3
sFilePath = sPath; Zdfruzl&`
sFileName = sName; T)#e=WcP]
this.nSplitter = nSpiltter; b3NEYn
>PS`;S!(
vu@@!cT6e
} )BeBxo7lv
-|DBO0q
jvQpfd
public String getSSiteURL() Vi=u}(*
{ ()MUyW"S#`
return sSiteURL; L3;cAb/
} /{R>o0oW
S*l=FRFI
%#7 ]
public void setSSiteURL(String value) s&d!+-\6_
{ wbQs>pc
sSiteURL = value; _aP2gH
} ~ugyUpY"
Y3.^a5o
jdf3XTw
public String getSFilePath() 3D-VePM=`
{ &gdhq~4#
return sFilePath; 7Z< 2`&c7
} ubs>(\`q"
]KM3G
RI2/hrW
public void setSFilePath(String value) =#T3p9
{ GdVrl[
sFilePath = value; YH,u*.I^/
} g1{2E<b5
rM0Idc.$&&
nV/;yl4e{
public String getSFileName() m;cgX#k5
{ fq?MnWc
return sFileName; =))VxuoN
} (DQ ]58&
miUjpXt
-uei nd]
public void setSFileName(String value) P,<pG[^K
{ *"d['V3
sFileName = value; ~.$ca.Gf
} @[v4[yq-
*J3Z.fq%:i
%~I%*=o[
public int getNSplitter() 2l}H=DZV
{ Oj1B @QE
return nSplitter; 9j>LU<Z
} /_mU%fl
:Aa5,{v_
$O^"OQ_@
public void setNSplitter(int nCount) ~m3Tq.sYrY
{ 6KE?@3;Om
nSplitter = nCount; U>hpYqf_
} UO(?EELm
} SnVb D<
~o27~R ]
.#{m1mr
/* xM:9XhH1
**Utility.java O ]!/fZ;(
*/ :yFmCLZaQ
package NetFox; l.uW>AoLh
m't8\fo^w
rm%MQmF
public class Utility { 534DAhpD=.
+[":W?j
7|DPevrk
public Utility() [5-3PuT&9
{ $T7(AohR
mvu$
y4%[^g~-
} ,56objaE
`Y,<[ Lnr
//线程睡眠 6&KcO:}-
public static void sleep(int nSecond) \hDjZ
{ xM_+vN*(
try{ cuQAXqXC@
Thread.sleep(nSecond); ]p*Fq^
} a{\<L/\
catch(Exception e) mJ'5!G
{ @DuSii#.S
e.printStackTrace (); %I#[k4,N
} rnP *}
} _ q^JjR
}8dS[-.
//日志 :+Tvq,/"
public static void log(String sMsg) Xz!O}M{4
{ \<%?=C'w~
System.err.println(sMsg); !"SuE)WM
} ]SL0Mn g8
ys9'1+9
-d*je{c|
public static void log(int sMsg) <xh";seL
{ zRFvWOxC\
System.err.println(sMsg); -DWnDku8=
} CD pLV:
} \@$V^;OP/
&5n0J
_)MbvF
/* vt(cC))
**TestMethod.java Qq<+QL|
*/ eT@,QA(3
package NetFox; k? !'OHmBL
s!?T$@a=
lr9s`>9
public class TestMethod { >#|%y>g .o
z K6'wL!!I
}TG=ZVi
public TestMethod() =j~Xrytn
{ ///xx/weblogic60b2_win.exe sEx`9_oZ
try{ <nJ8%aY,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]]50c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '7UIzk|
SiteFileFetch fileFetch = new SiteFileFetch(bean); XX'mM v
fileFetch.start(); `J-&Y2_/k
} %YwIR.o
catch(Exception e){e.printStackTrace ();} G$E+qk nJL
}5=tUfh)]'
li&&[=6A
} 94xWMX2
]SG(YrF
3?s1Yw>?
public static void main(String[] args) WoWmmZ
{ ~JTp8E9kw
new TestMethod(); l [ Navw
} /EV _Y|(-
} O_^;wey0}?
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