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)); DYoGtks(
} F'-XAI <3
for(int i=0;i<nEndPos.length-1;i++) 4hxa|f
{ yp[,WZt
nEndPos = nStartPos[i+1]; +`iJ+
} kE:{#>[Uz
nEndPos[nEndPos.length-1] = nFileLength; &WeN{
} tH~>uOZW
} M?AKJE j5
\8g= Ix
Ldj*{t`5
//启动子线程 gWL`J=DiU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >=:^N-a
for(int i=0;i<nStartPos.length;i++) {9@u:(<X9
{ H@u5&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LIrebz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a`[9<AM1#
nStartPos,nEndPos,i); h?H|)a<^9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $wn0oIuW
fileSplitterFetch.start(); [k0/ZfFwV
} h#c7v!g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t 4VeXp6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1=,y+Xpw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7#c4.9b?
nEndPos = " + nFileLength); hzU(XW
// fileSplitterFetch[nPos.length-1].start(); ExMd$`gW
#WJ*)$A@&
1{wbC)
//等待子线程结束 $$uMu{?0i
//int count = 0; vt nT
//是否结束while循环 ~L>86/hP,N
boolean breakWhile = false; !Qf*d;wxn(
i"=lxqWeaV
dWY{x47
while(!bStop) m@u%3*:
{ yn"4qC#Z
write_nPos(); tj*/%G{Y
Utility.sleep(500); +KD7Di91<K
breakWhile = true; -SfU.XlZl
x7Gf):,LK
ktS^^!,l%
for(int i=0;i<nStartPos.length;i++) L|}s Z\2!
{ [[w |
if(!fileSplitterFetch.bDownOver) nMZ)x-
{ qGX#(,E9;
breakWhile = false; +jK-k_
break; oH!O{pQK}
} ,QpFVlPU
} N'-[>w7vK2
if(breakWhile) s2GF*{
break; 9zS
1q@R04i
3Pllxq<n
//count++; K[ [6A:
//if(count>4) "DA%vdu
// siteStop(); qTN%9!0@9
} O`@- b#
,i??}Wm5G
.}v" `>x
System.err.println("文件下载结束！"); T1*.3_wtP
} k].swvIi
catch(Exception e){e.printStackTrace ();} D7T|K :F)
} E>f{j:M
l)dE7$H
$B_%MfI
//获得文件长度 gua7<z6=eh
public long getFileSize() (ie%zrhS
{ -*MY7t3
int nFileLength = -1; jU7[z$GX
try{ ""XAUxo
URL url = new URL(siteInfoBean.getSSiteURL()); *U]&a^N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xY#J((-iH
httpConnection.setRequestProperty("User-Agent","NetFox"); fK+ 5
pjX=:K|
[U8/nT
int responseCode=httpConnection.getResponseCode(); *4Ldh}S!
if(responseCode>=400) 'j<u0'K@
{ ]X77?Zz9
processErrorCode(responseCode); N0-J=2
return -2; //-2 represent access is error N0Y4m_dm*
} y.J>}[\&x
}8#Ed;%K
bT&{8a
String sHeader; `=P_ed%&'
Mmu#hb|W
FZ?eX`,
for(int i=1;;i++) BZHoRd{EH
{ MTZCI}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z#-N$%^F
//Utility.log(in.readLine()); kx?Yin8K
sHeader=httpConnection.getHeaderFieldKey(i); [M,4qe8,}
if(sHeader!=null) `D |/g;
{ =CRptk6tS
if(sHeader.equals("Content-Length")) b<~-s sL7a
{ bTmhz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #` gu<xlW
break; *bf 5A9
} 2Kz$y JTp
} DE?k|Get2
else mV`R'*1UC
break; ~M-L+XZl(
} q,@# cQBV
} e4SS'0|
catch(IOException e){e.printStackTrace ();} 6bhb_U'f
catch(Exception e){e.printStackTrace ();} o]Ne|PEpO
xZ P SUEG
BJWlx*U]
Utility.log(nFileLength); a;Y:UwD9*
t^"8M6BqC;
6h)_{| L)
return nFileLength; #jg-q|nd
} U\H[.qY-
'QG`^@Z
*)-@'{]uB
//保存下载信息（文件指针位置） 452kE@=49
private void write_nPos() LdG?kbJ&y
{ qX5>[qf-
try{ [YULvWAJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); H Eq{TUTr
output.writeInt(nStartPos.length); ;9mRumLG"
for(int i=0;i<nStartPos.length;i++) UTKyPCfj
{ zHZfp_I
// output.writeLong(nPos); [znN'Fg:"
output.writeLong(fileSplitterFetch.nStartPos); V<S6a
output.writeLong(fileSplitterFetch.nEndPos); /qy6YF8;y
} <i</pA
output.close(); ygIn6.p
} %K|f,w=m
catch(IOException e){e.printStackTrace ();} M' z.d
catch(Exception e){e.printStackTrace ();} g^+p7G
} LxhS 9
(KyOo,a
re[5lFQ~Z
//读取保存的下载信息（文件指针位置） wrgB =o
private void read_nPos() 2}pZyS
{ >9A18xC
try{ b.RU%Y#>\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5uQ+'*xN%
int nCount = input.readInt(); [(x*!,=
nStartPos = new long[nCount]; {:!>Y1w>
nEndPos = new long[nCount]; k-=lt\?
for(int i=0;i<nStartPos.length;i++) Eqz|eS*6
{ z+Fu{<#(
nStartPos = input.readLong(); #z.n?d2Gd
nEndPos = input.readLong(); o}:x-Y
} fm-m?=
input.close(); IxCesh
} d-1D:Hs?
catch(IOException e){e.printStackTrace ();} Z3{1`"\<K
catch(Exception e){e.printStackTrace ();} XJeWhk3R9
} ptT-{vG
02t({>`
4;Ucas6
private void processErrorCode(int nErrorCode) E|c(#P{
{ TYGI f4z
System.err.println("Error Code : " + nErrorCode); 56<UxIa~
} tdxzs_V,-
;hDk gp
uxD3+Q
//停止文件下载 Gh=I2GSo
public void siteStop() Jk(V ]
{ /Z:NoTGn
bStop = true; bl a`B=r
for(int i=0;i<nStartPos.length;i++) x6R M)rr
fileSplitterFetch.splitterStop(); 6H'A]0
G4SA u
W..*!UGl
} N? Jy
} 46D`h!7L
//负责部分文件的抓取 Dch\k<Te
**FileSplitterFetch.java uOzoE_i
*/ G8+&fn6
package NetFox; G3^<l0?S
>eG<N@13p
v2rO>NY4
import java.io.*; $aJ6i7C,j}
import java.net.*; L$_%T
<<?32r~
o=7,U/{D!
public class FileSplitterFetch extends Thread { 6ScB:8M
GB Yy^wjU
ph5{i2U0
String sURL; //File URL N`efLOMl]
long nStartPos; //File Snippet Start Position @!dIa1Q"
long nEndPos; //File Snippet End Position d"Zu10
int nThreadID; //Thread's ID 1qNO$M
boolean bDownOver = false; //Downing is over N gF7$@S
boolean bStop = false; //Stop identical "LB MYZ
FileAccessI fileAccessI = null; //File Access interface :5&D6
4t(/F`
g?"QahHG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o 7kg.w|
{ TSewq4`K
this.sURL = sURL; a-|pSe*rx
this.nStartPos = nStart; ``jNj1t{}
this.nEndPos = nEnd; \:{K",2
nThreadID = id; KHZ[drb6$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B@M9oNWHu
} i,ZEUdd*_
y*^UGJC:
\78^ O
public void run() ULz<P
{ .%n_{ab1
while(nStartPos < nEndPos && !bStop) @;OsHudd
{ 1Zc=QJw@
,L-/7}"VHA
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try{ ~wuCa!!A
URL url = new URL(sURL); td7(444]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AA[1[
httpConnection.setRequestProperty("User-Agent","NetFox"); %Ve@DF8G
String sProperty = "bytes="+nStartPos+"-"; 2LUsqL\m}.
httpConnection.setRequestProperty("RANGE",sProperty); lfDd%.:q4S
Utility.log(sProperty); ^L$`)Ja
nm#23@uZ4K
X<8|uP4
InputStream input = httpConnection.getInputStream(); 9dA+#;?
//logResponseHead(httpConnection); 8d5#vm
Rw0|q
rd0Fd+t/
byte[] b = new byte[1024]; dT'}:2
int nRead; trrNu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0=HB!{@
{ %HpPTjAW
nStartPos += fileAccessI.write(b,0,nRead); }:faHLYT
//if(nThreadID == 1) 8[J%TWq%9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]dGH i \
} 0'*{BAWx
]*| hd/j
of*T,MUI
Utility.log("Thread " + nThreadID + " is over!"); uQdH():
bDownOver = true; z{OL+-OY
//nPos = fileAccessI.write (b,0,nRead); B(Yg1jAe
} 4_-&PZ,d
catch(Exception e){e.printStackTrace ();} 3LfF{ED@
} m]U
} KdozB!\
aPxSC>p
9~Sa7P
//打印回应的头信息 ]>)shH=Yx
public void logResponseHead(HttpURLConnection con) l[[`-f8j
{ H][TH2H1
for(int i=1;;i++) :MF`q.:X
{ kum@cA
String header=con.getHeaderFieldKey(i); f3!Oc
if(header!=null) xSN;vrLHR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N~/X.D4e#
Utility.log(header+" : "+con.getHeaderField(header)); E8kD#tL
else IIY_Q9in
break; }Y!V3s1bm
} iSf%N>y'K
} \m)s"Sh.
%52e^,//
XuJyso9kA
public void splitterStop() d4IQ;u
{ bX38=.up
bStop = true; C{*?
} b&`~%f-
>(H:eRKq
x/{-U05
} '{cND
$,Xn@4
ASi2;Q_{_
/* I52nQCXi
**FileAccess.java 0);5cbV7i
*//文件访问(定位，写) -<x%
package NetFox; fsOlg9
import java.io.*; PtuRXx
BDfMFH[1
xS@jV6E~
public class FileAccessI implements Serializable{ .&b^6$dC
Hz,Gn9:p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GtmoFSZ
RandomAccessFile oSavedFile; _hV34:1F
long nPos; _)vX_gCi
KF *F
m$[:J
public FileAccessI() throws IOException ?3DFm
{ 5u9lKno
this("",0); c(Y~5A{TXO
} bl!pKOY
l5^Q
Yl au
public FileAccessI(String sName,long nPos) throws IOException W<&/5s
{ 5KB Z-,
oSavedFile = new RandomAccessFile(sName,"rw"); nWCJY:q;5
this.nPos = nPos; /z^v%l
oSavedFile.seek(nPos); th*!EFA^o
} ]EF"QLNN(
'uz o[>p
R $<{"b
public synchronized int write(byte[] b,int nStart,int nLen) *j(fk[,i
{ Q3+%8zZI
int n = -1; 81#x/&E]
try{ `Qb!W45
oSavedFile.write(b,nStart,nLen); )2EvZn
n = nLen; kS{k=V&hf_
} <^;~8:0]
catch(IOException e) FiReb3zR
{ A1B[5a*o!
e.printStackTrace (); _\dC<K *>
} ?8grK
ecl6>PS$'
)$Ib6tYY
return n; ]Y$Wv9S6
} nO`[C=|
h] )&mFiE"
&/' O?HWl
} jm&[8ApW
.3+8Ip#z
,>(X}Q
/* zuMz6#aCC8
**SiteInfoBean.java ByoI+n* U
*/ -[>J"l
package NetFox; se3EI1e
ec^{ez@`
kQ\l7xd
public class SiteInfoBean { o\tw)_ >
lgt&kdc%o
&9v8
private String sSiteURL; //Site's URL Q!-"5PX
private String sFilePath; //Saved File's Path VZamR}x
private String sFileName; //Saved File's Name dXn$XGF%R
private int nSplitter; //Count of Splited Downloading File N>L)2WKFT
r.LOj6c
NV{= tAR
public SiteInfoBean() xZq, kP^
{//nSplitter的缺省值为5 ?gU-a
//default value of nSplitter is 5 jl;N Fk%
this("","","",5); l8Yr]oNkz
} FLsJ<C~/~
-=:tlH n
=dKk #*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #Sy~t{4
{ i%f C`@
sSiteURL= sURL; _{LmJ?!
sFilePath = sPath; 7]5+%[Dg!
sFileName = sName; es69P)
this.nSplitter = nSpiltter; "E5=AWd
'Q7t5v@FF
jfvlkE-uK
} |d42?7}
Kzt:rhiB
='Oxy
public String getSSiteURL() (Ww SisC~
{ 92,@tNQQ}
return sSiteURL; D][I#vh
} fe6Op
mT j
qncZpXw^
public void setSSiteURL(String value) us8ce+
{ H-WNu+
sSiteURL = value; l)KN5V
} SzG %%CXH_
3uvl'1(%J
rP6k}
public String getSFilePath() l~f9F`~'
{ rw@N=`4P
return sFilePath; jt @2S
} ,pZz`B#
^^xzaF
oe9S$C;$'
public void setSFilePath(String value) =AHV{V~
{ E}36
sFilePath = value; |~Awm"
} u91
``Um$i~e%
Ex}TDmTu
public String getSFileName() H0Sm4
{ b?9'-hK<
return sFileName; (d <pxx
} >qI:
ZkMHy1
(Zy=e?E,
public void setSFileName(String value) hL;??h,!_
{ 1mEW]z
sFileName = value; i-k(/Y0
} 7` XECIh
~F~hgVS5
ov>`MCS,v
public int getNSplitter() a ?wg~|g
{ jd+HIR
return nSplitter; Y k"yup@3
} R,zp&L
;ZrFy=Iv
+hT9V1'-D
public void setNSplitter(int nCount) 6~k qU4lL
{ r^\Wo7q
nSplitter = nCount; 52 DSKL
} 8HSGOs =8
} Gg7ZSB 7
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twTRw:.!f
/* \g@jc OKU
**Utility.java 4MgG]
*/ PzLV}
package NetFox; & *&
JAL"On#c#0
<DdzDbgax
public class Utility { 'ka"0~:NS{
Au?(_*/0
Yr:$)ap
public Utility() *-_joAWTG
{ IG@@CH
(b1rd
X`daaG_l
} W!Rr_'yFe)
,Hsu;I~
//线程睡眠 ~U4;YlQP
public static void sleep(int nSecond) 0k|/]zfb
{ *;(GL
try{ v\COl*
Thread.sleep(nSecond); SYK?5_804
} (pQ$<c
catch(Exception e) ^m^,:]I0P
{ '8Lc}-M4
e.printStackTrace (); p WKpc
} &[}5yos r
} YWa9|&m1
nHF
//日志 Jc9^Hyqu&
public static void log(String sMsg) $2*&\/;-E!
{ SB!m&;Tb
System.err.println(sMsg); o&:n>:im
} %PU{h
qv+}|+aL:
!yTjO
public static void log(int sMsg) #9hSo
{ V-9z{
System.err.println(sMsg); qS2]|7q?Tc
} xZ&S7G1
} qT_E=)1
?B,B<@='%
s}Sxl0
/* x1*@PiO,.
**TestMethod.java Z{.L_]$I
*/ /B9jmvj`
package NetFox; bk-aj'>+
u&Dd9kMz
iJK rNRj
public class TestMethod { 4K*DEVS
]z/
'Xzi$}E D
public TestMethod() ^-7{{/
{ ///xx/weblogic60b2_win.exe H~"XlP
try{ g|l|)T.s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y3wL EG%,:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rO{"jJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); j~Xn\~*n
fileFetch.start(); 4&LoE~
} x@>^c:-f
catch(Exception e){e.printStackTrace ();} =Hs~fHa)
cYEe`?*
ud.Bzg:/
} 3#T_(
V5ihplAk
OKq={l
public static void main(String[] args) Y_Lsmq2!
{ OECXNx
new TestMethod(); X{riI^(
} YPq`su7m9
} *:A)j?(
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