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)); b]?5r)GK
} +dLUq2
for(int i=0;i<nEndPos.length-1;i++) SVwxK/Fci
{ zmZU"eWp)
nEndPos = nStartPos[i+1]; qF^P\cD
} k@%5P-e}
nEndPos[nEndPos.length-1] = nFileLength; [4C_iaE
} %pWJ2J@
} 6oQ7u90z*
'LG\]h>+)
PW%ith1)<
//启动子线程 5l@}1n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zqU$V~5;rG
for(int i=0;i<nStartPos.length;i++) F$4=7Njv
{ ~}p k^FA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |UlR+'rl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z%ZOAu&p
nStartPos,nEndPos,i); um]N]cCD`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WxD$k3U
fileSplitterFetch.start(); 3,i`FqQa
} m,hqq%qz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `_/1zL[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }Gb^%1%M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NE`;=26c
nEndPos = " + nFileLength); v@2?X4n
// fileSplitterFetch[nPos.length-1].start(); S9[Up}`
HW_2!t_R
-KbO[b\V
//等待子线程结束 ( Ygy%O%
//int count = 0; liB~vdqj
//是否结束while循环 .'+JA:3R
boolean breakWhile = false; |1!|SarM{B
8zeD%Uv
h\)ual_r[j
while(!bStop) N/0Q`cQ-
{ %^I 7=
write_nPos(); P:'y}a-
Utility.sleep(500); 1Ogtzf
breakWhile = true; tx3p, X
-jTK3&5
A}pe>ja
for(int i=0;i<nStartPos.length;i++) [sPLu)q2
{ Oh`Pf;.z%
if(!fileSplitterFetch.bDownOver) Y'6P ~C;v
{ lg (>n&
breakWhile = false; xr)m8H
break; W89J]#v)k
} wE <PXBl\b
} :e_yOT}}
if(breakWhile) /KJWo0zo
break; eLN(NSPoS
q=BAYZ\`
=PBJ+"DQs
//count++; \w{fq+G
//if(count>4) BxxqzN+
// siteStop(); g'eJN
} s.}:!fBk
A56aOI=
QF_K^(
System.err.println("文件下载结束！"); %}Ob~m>P
} na4^RPtN\e
catch(Exception e){e.printStackTrace ();} 5th\_n}N2/
} ;%i.@@:IQ
$0E_4#kwB
fNi_C"<
//获得文件长度 m4T`Tg#P
public long getFileSize() k{$Mlt?&-
{ {I_I$x_
int nFileLength = -1; 9_S>G$9D
try{ G9\@&=
URL url = new URL(siteInfoBean.getSSiteURL()); .7GAGMNS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fL1EQ)
httpConnection.setRequestProperty("User-Agent","NetFox"); HV6'0_R0
)%5T*}j
"Q@ZS2;A
int responseCode=httpConnection.getResponseCode(); {YgB?kt5
if(responseCode>=400) =i)k@w_(x
{ 3~!PJI1
processErrorCode(responseCode); lFLiW
return -2; //-2 represent access is error Z66@@?`
} @=[SsS
~\m|pxcj
Q:B:
String sHeader; MoP0qNk
:3Z"Qk$uR
m<;&B
for(int i=1;;i++) az]S&\i7T
{ 4RqOg1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7L:$Amb_F
//Utility.log(in.readLine()); M-df Gk
sHeader=httpConnection.getHeaderFieldKey(i); b1;80P/:D
if(sHeader!=null) xe6 2gaT
{ 0 .dSP$e
if(sHeader.equals("Content-Length")) <3>Ou(F
{ f13%[RA9N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F+S;u=CKx
break; #9Z*.
} r=+r5k"`
} M+ gYKPP
else }cE,&n
break; \~zTc_
} fD<3Tl8U0
} ~J6c1jG
catch(IOException e){e.printStackTrace ();} HzT"{N9
catch(Exception e){e.printStackTrace ();} dHnId2@#
% ;2x.
,bCPO`45
Utility.log(nFileLength); :(Feg2c
g4I&3 M
>b0e"eGt
return nFileLength; v>$GVCY
} Mnaoh:z
quU%9m \S`
3e:"tus~
//保存下载信息（文件指针位置） atFj Vk^
private void write_nPos() 59p'Ega.
{ t_WNEZW7f
try{ PZRpH
output = new DataOutputStream(new FileOutputStream(tmpFile)); fdzD6KZI
output.writeInt(nStartPos.length); v.,C"^W
for(int i=0;i<nStartPos.length;i++) 8Hs>+Udl
{ ^^%sPtp
// output.writeLong(nPos); /z,sM"d
output.writeLong(fileSplitterFetch.nStartPos); q0w5ADd
output.writeLong(fileSplitterFetch.nEndPos); w-|i8%X
} z8= Gc$w!
output.close(); ts%@1Y?
} >wM%|j'
catch(IOException e){e.printStackTrace ();} 5 8p_b
catch(Exception e){e.printStackTrace ();} oWo"`"P
} lb&tAl"D
}jfU qqFd
9 YU7R)
//读取保存的下载信息（文件指针位置） $[[6N0}*:
private void read_nPos() B.K"1o
{ yK0Q,
try{ D_9&=aa'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 91%+Bf()J6
int nCount = input.readInt(); 1U~AupHE
nStartPos = new long[nCount]; n@5pS3qZ
nEndPos = new long[nCount]; V@84Cb
for(int i=0;i<nStartPos.length;i++) sxO_K^eD
{ nV McHN
nStartPos = input.readLong(); [lQp4xgxi
nEndPos = input.readLong(); %g0"Kj5
} Fx0K.Q2Y0
input.close(); R/b)hP~
} H<%7aOwO2
catch(IOException e){e.printStackTrace ();} S]9:3~
catch(Exception e){e.printStackTrace ();} ?9v!UT&#
} X&^t 8
)(\5Wk9(
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private void processErrorCode(int nErrorCode) Q2^}NQO=
{ vjZX8KAiZ
System.err.println("Error Code : " + nErrorCode); 5xLuuKG
} 1<<`T%&
cpFw]w%]
E^1uZI\z
//停止文件下载 {^"c>'R
public void siteStop() uc=-+*D'I
{ W5_t/_EWD
bStop = true; #rzxFMA"
for(int i=0;i<nStartPos.length;i++) `8xe2=Ub
fileSplitterFetch.splitterStop(); rA8neO)
^z9ITGB~tV
h k(2,z
} f Nm Sx
} !7AW_l9`i
//负责部分文件的抓取 B:qZh$YN
**FileSplitterFetch.java F{]dq/{
*/ cpgHF`nt
package NetFox; R7ZxS
)3'/g`c
2!7wGXm~U
import java.io.*; /]F3t]FlC
import java.net.*; 1f~unb\Gg
Xy_+L_h^
#XQEfa
public class FileSplitterFetch extends Thread { EtcAU}9
k/j]*~"
Xv]O1fcI
String sURL; //File URL 2o6KVQ
long nStartPos; //File Snippet Start Position ;5PXPpJ
long nEndPos; //File Snippet End Position +QtK "5M
int nThreadID; //Thread's ID ~U~KUL|
boolean bDownOver = false; //Downing is over c[3sg
boolean bStop = false; //Stop identical LUHj3H
FileAccessI fileAccessI = null; //File Access interface \n6#D7OV
CbS- Rz:
#=OKY@z/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uPr@xff
{ x`WP*a7Fk]
this.sURL = sURL; P`@d8%*;
this.nStartPos = nStart; ?E^~z-
this.nEndPos = nEnd; sn@gchO9s
nThreadID = id; QPg QM6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k_ UY^vz.
} [ZZ~^U5
8jMw7ti
4sP0oe[h
public void run() 7!]$XGz[
{ K``MS
while(nStartPos < nEndPos && !bStop) plh.-"
{ Z[)t34EY"
Ckj2$c~
Q]S~H+eRy
try{ ]e$mTRi*
URL url = new URL(sURL); )iNMjg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ %cW ?@
httpConnection.setRequestProperty("User-Agent","NetFox"); f7Y0L8D
String sProperty = "bytes="+nStartPos+"-"; s )POtJ<
httpConnection.setRequestProperty("RANGE",sProperty); Qj.]I0d
Utility.log(sProperty); %YkJA:
]>tYU
$5yH(Z[[
InputStream input = httpConnection.getInputStream(); (dd+wx't
//logResponseHead(httpConnection); N7Kq$G2O
i,r O3Jn
P"Lk(gY
byte[] b = new byte[1024]; B7zyMh
int nRead; {;4Y5kj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IFcxyp
{ L.ScC
nStartPos += fileAccessI.write(b,0,nRead); mk(O..)2
//if(nThreadID == 1) W/!M eTU&E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @}eEV[Lli
} xP#vAR
!~Gx@Ro
O=~8+sa
Utility.log("Thread " + nThreadID + " is over!"); s~ ||Vv!
bDownOver = true; Yv<'QC
//nPos = fileAccessI.write (b,0,nRead); PP)iw@9j
} ~QgyhJM_h=
catch(Exception e){e.printStackTrace ();} q.0Evr:
} yMaU`z
} R= ,jqW<
w0qrh\3du
G&,1 NjSi
//打印回应的头信息 I><B6pIR
public void logResponseHead(HttpURLConnection con) ha[c<e]uo[
{ sZe$?k|
for(int i=1;;i++) nhV\<
{ Yc~(Wue
String header=con.getHeaderFieldKey(i); .#^ta9^t7
if(header!=null) Y-2IAJHS8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A*+pGQ
Utility.log(header+" : "+con.getHeaderField(header)); { 0\Ez}
else xgDd5`W
break; <PLQY
} 44Dytpvg
} /{1sU}k-
"PgVvm#w'
M3XG s|gw
public void splitterStop() 9S'u1%
{ *Bfo"["0.
bStop = true; `iHyGfm
} u<L<o2
wnioIpRkh
rX7GVg@H
} Lql2ry$Wa
e p jb
n[S-bzU^t
/* VSx9aVPkC
**FileAccess.java yv[3&E?
*//文件访问(定位，写) @h&:xA56
package NetFox; Cn"_x
import java.io.*; ]I,(^Xq3a(
"Jahc.I
DCsamOA~
public class FileAccessI implements Serializable{ awXK9}.
L@5sY0 M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A%[e<vj9
RandomAccessFile oSavedFile; -F. c<@*E
long nPos; \gsJ1@
zG0]!A
Z~0TO-Q
public FileAccessI() throws IOException vjL +fH<0:
{ $u~*V
this("",0); /Nc)bF%gX
} hW!2C6
vfd<qdi3p(
~6"=d
public FileAccessI(String sName,long nPos) throws IOException A"B#t"
{ 4#Xz-5v
oSavedFile = new RandomAccessFile(sName,"rw"); T@Bu Fr`]<
this.nPos = nPos; gSa!zQN6
oSavedFile.seek(nPos); D6dliU?k
} 3PjX;U|
\#h{bnx
b'ZzDYN
public synchronized int write(byte[] b,int nStart,int nLen) /F$E)qN7n
{ hj=qWGRgI
int n = -1; ;reBJk
try{ 4@+']vN4
oSavedFile.write(b,nStart,nLen); R XCjYzt
n = nLen; uHsLlfTn
} !|W.YbS
catch(IOException e) ]v/pMg#-
{ 4ClSl#X#i
e.printStackTrace (); **\?-*c=U
} dVPY07P
=van<l4b#n
K5rra%a-7
return n; ]h#QA;
} <-mhz`^
it-]-=mqb
!>"fDz<w`
} $|g ;
Q5hOVD%
bsm/y+R
/* fLpWTkr0
**SiteInfoBean.java SA#01}&p
*/ mr2Mu
package NetFox; c|d,:u#
RH:vd|q+
}VRl L>HAC
public class SiteInfoBean { &qK:LHhj
gkX7,J-0
Z^}[CQ&Am
private String sSiteURL; //Site's URL (t\U5-w
private String sFilePath; //Saved File's Path 6O/c%1VHA3
private String sFileName; //Saved File's Name L+VQtp&"
private int nSplitter; //Count of Splited Downloading File nbB*d@"
:5['V#(o
6" <(M@
public SiteInfoBean() ByuBZ!m
{//nSplitter的缺省值为5 Q-!gO
//default value of nSplitter is 5 9J~\.:jH-
this("","","",5); ^%!SKhRIK
} [=BMvP5
'l`prp3
$+f=l~/s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \gkhSLq
{ a|=^
sSiteURL= sURL; q*4U2_^.
sFilePath = sPath; UlXxG|
sFileName = sName; Ue60Mf
this.nSplitter = nSpiltter; W8$0y2
JBLUX,
~".@;Q
} -|^)8
"&/2@
$/|) ,n
public String getSSiteURL() "oNl!<ep
{ z6l'v~\
return sSiteURL; ;Vc|3
} pqb`g@
oQ,<Yx%E3
-aVC`
public void setSSiteURL(String value) 7n.Oem
{ +0z7}u\x
sSiteURL = value; &Jb\}c}
} =EMB~i
);VuZsmi
'sH_^{V2
public String getSFilePath() Dol{y=(3e
{ M2|h.+[Q
return sFilePath; pc0{
} \.O&-oi
/z4c>)fV
dd<l;4(
public void setSFilePath(String value) fV5$[CL1
{ @-L]mLY
sFilePath = value; <7F-WR/2n
} -5 PVWL\
^7gKs2M
5!fYTo|G>
public String getSFileName() V0_tk"
{ `62v5d*>a
return sFileName; ]q{_i
} e }?.3,?
`3i>e<m~
~Ay)kv;
public void setSFileName(String value) }URdoTOvb
{ -wiQd@X
sFileName = value; r4X}U|s!0
} >d p/
0t^FM<7G
e~zgH\`
public int getNSplitter() 4BCe;Q^6
{ X\P%C
return nSplitter; rx2'].
} px K&aY8
[M~tH *4"
77O$^fG2
public void setNSplitter(int nCount) 3< ?+Yhq
{ mW%8`$rVEO
nSplitter = nCount; Zyz#xMmM
} e6j1Fa9
} . &j+&
=eQB-Xe8Y
H575W"53
/* Uw.')ZY=
**Utility.java OA3J(4!"W
*/ <N=k&\
package NetFox; T[|#DMg$F
kx;X:I(5&P
2 3PRb<q
public class Utility { +zMPkbP6
}b(hD|e
W`Gbo uxd
public Utility() ,]2?S5R
{ uxU-N
1WMZ$vsQUb
fAULuF
} i86:@/4~F
nd8<*ru$
//线程睡眠 _:m70%i
public static void sleep(int nSecond) _Rii19k
{ jy!]MAP#Gk
try{ M#'7hm6
Thread.sleep(nSecond); ~][~aEat;V
} /(BS<A
catch(Exception e) #Zm`*s`
{ eVfD&&@
e.printStackTrace (); L[2qCxB'^
} 4P3RRS
} `nyz,
U7x
//日志 Z?o0Q\}1
public static void log(String sMsg) $vXY"-k
{ ]vQa~}
System.err.println(sMsg); ?C2(q6X+s
} ED>7
o!BCR:
bPFGQlmIO
public static void log(int sMsg) Y5GN7.
{ XE2Un1i}j1
System.err.println(sMsg); (sKg*G2
} ~%*l>GkP*
} ">Qxb.Y}
h~#F2#.
>k"O3Pc@
/* B1}i0pV,,
**TestMethod.java */K[B(G
*/ En&7e
package NetFox; _K#7#qp2
KcV"<9rE
l5w^rj
public class TestMethod { oqwW
j4i$2ZT'
WDY\Fj
public TestMethod() )2).kL>
{ ///xx/weblogic60b2_win.exe X{#^O/
try{ HCOsVTl,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "T5jz#H#/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ByjfPb#
SiteFileFetch fileFetch = new SiteFileFetch(bean); l#cVQ_^"
fileFetch.start(); *m"@*O'
} |E K6txRb
catch(Exception e){e.printStackTrace ();} yam'LF
w31O~Ve
LeN }Q
} R~oY R,L;
9ls1y=M8J
<tTNtBb
public static void main(String[] args) o Rk'I
{ xqk(id\&
new TestMethod(); hRuiuGC
} u*l>)_HD
} fQ~~%#z1
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