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)); NXb_hF
} FZ'|z8Dm
for(int i=0;i<nEndPos.length-1;i++) -Zc 6_]F|
{ aRPgo0,W1
nEndPos = nStartPos[i+1]; cf)2GoV>e
} g N76
nEndPos[nEndPos.length-1] = nFileLength; DP**pf%j
} 12BTZ
} H)S" `j
~?4'{Hc'
`p1szZD&
//启动子线程 ZnSDq_Uk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [<`K%1GQ
for(int i=0;i<nStartPos.length;i++) H~UxVQLPp
{ {)nm {IV,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G&$+8r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Sd/?xyF1(
nStartPos,nEndPos,i); n:d]Z2b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rM<|<6(L
fileSplitterFetch.start(); u&Ts'j
} |:Gz9u+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .|`JS?L[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d1VNTB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CnyCEIO-
nEndPos = " + nFileLength); qDZ?iTHQq
// fileSplitterFetch[nPos.length-1].start(); m?bd6'&FR
YSERQo
xp-.,^q\w
//等待子线程结束 p.^glz>B
//int count = 0; 3`[f<XaL
//是否结束while循环 mpfc2>6Il.
boolean breakWhile = false; '7AlE!7%
Q-o}Xnj*!L
spter35b[
while(!bStop) ^*(*tS|M
{ A.tONPi
write_nPos(); lj0"2@z3"E
Utility.sleep(500); VL=.JwK
breakWhile = true; [mX/]31
}9yAYZ0q{b
)7@f{E#w
for(int i=0;i<nStartPos.length;i++) Lt>"R! "x
{ d\&{Ev9v
if(!fileSplitterFetch.bDownOver) LdxrS5
{ `F5iZWW1
breakWhile = false; .U|irDO
break; nI4Kuz`dF
} R!IODXP=
} ??eSGQ|
if(breakWhile) "`]G>,r_
break; ) *Mr{`
+k|t[N
JW[y
//count++; _Kdqa%L !
//if(count>4) (XW\4msB)I
// siteStop(); 6d/;GyG
} Gq%q x4
3\_ae2GW
KP{|xQ>
System.err.println("文件下载结束！"); B1dVHz#
} ~ED8]*H|`
catch(Exception e){e.printStackTrace ();} ;|_aACina
} 0G`_dMN
Y"~Tf{8
Y+5nn
//获得文件长度 8|kr|l
public long getFileSize() e~C5{XEE
{ Sq^f}q
int nFileLength = -1; _~V7m
try{ d 7vD
URL url = new URL(siteInfoBean.getSSiteURL()); 4FSA:]o-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qgREkb0
httpConnection.setRequestProperty("User-Agent","NetFox"); XFpII45
&KinCh7l L
PI_MSiYQ
int responseCode=httpConnection.getResponseCode(); zUX%$N+w}>
if(responseCode>=400) sq `f?tA?
{ KwGk8$ U
processErrorCode(responseCode); gB/4ro8
return -2; //-2 represent access is error q =sEtH=
} (iub\`
?+#|h;M8
a@(4X/|
String sHeader; z}I=:
$:IOoS|e
~ [L4,q
for(int i=1;;i++) l&3f<e
{ _'pow&w~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $="t7C9S
//Utility.log(in.readLine()); 2R9AYI
sHeader=httpConnection.getHeaderFieldKey(i); $HVus=D"
if(sHeader!=null) ~uqpF-.
{ WAr;g?Q8
if(sHeader.equals("Content-Length")) 69#mj*p@+
{ mS?.xu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I(LBc
break; h| q!Qsnj'
} w`_cmI
} ffMh2
else v4M1uJ8
break; ?,GCR1|4
} HJ4T! `'d
} 7ux0|l
catch(IOException e){e.printStackTrace ();} {OFbU
catch(Exception e){e.printStackTrace ();} /^_~NF#
&5JTcMC^
+ob<? T
Utility.log(nFileLength); 9 0PF)U
.|>zQ(7YC
ee7#PE]}
return nFileLength; |'@c ~yc
} `PML4P[
}dnO7K
I+nKaN+8i
//保存下载信息（文件指针位置） kU uDA><1
private void write_nPos() +/!kL0[v
{ Ik{[BRzUgt
try{ @tv3\eD
output = new DataOutputStream(new FileOutputStream(tmpFile)); [[uKakp
output.writeInt(nStartPos.length); VVY#g%(K
for(int i=0;i<nStartPos.length;i++) n-X;JYQW
{ >K]s)VuWR
// output.writeLong(nPos); 'Xj9sAB
output.writeLong(fileSplitterFetch.nStartPos); &f12Q&jY7
output.writeLong(fileSplitterFetch.nEndPos); <{$0mUn;s|
} M0Eq 7:Ba
output.close(); -M]NdgI
} \#1*r'V8
catch(IOException e){e.printStackTrace ();} ]/byz_7]
catch(Exception e){e.printStackTrace ();} Fh2$,$ 2
} xd[GJ;xvs
fP|rD[
gz{~\0y
//读取保存的下载信息（文件指针位置） | %E\?-TK
private void read_nPos() }M3f ?Jv
{ .MNi)+
try{ <*D{uMw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,&+"|,m
int nCount = input.readInt(); Gyo[C98
nStartPos = new long[nCount]; 66A}5b4)]
nEndPos = new long[nCount]; oW0A8_|9
for(int i=0;i<nStartPos.length;i++) |>w>}w`~
{ :X1~
nStartPos = input.readLong(); +{b!,D3sa*
nEndPos = input.readLong(); ?&qa3y)wX:
} 1oD1ia#
input.close(); &yu3nA:7D
} c eH8
catch(IOException e){e.printStackTrace ();} Xz/5Wis4
catch(Exception e){e.printStackTrace ();} z^@.b
} $bf&ct*$h
)C?bb$ G
$e(]L(o;
private void processErrorCode(int nErrorCode) z"cF\F
{ &/%A 9R,
System.err.println("Error Code : " + nErrorCode); XctSw
} . X(^E
x3./
Cxn<#Kf\-<
//停止文件下载 *t_"]v-w
public void siteStop() q_0So}
{ ;3\oU$'
bStop = true; E;$;g#ksf
for(int i=0;i<nStartPos.length;i++) BQX6Q<
fileSplitterFetch.splitterStop(); nIRJ5|G(
rE:"8d}z
h$F.(NIYe
} zDEX `~c
} J<p.J3I
//负责部分文件的抓取 to}g4
**FileSplitterFetch.java 1_AB;^
*/ dv?ael^
package NetFox; i5f8}`w
$P=B66t ^
CV9o,rL
import java.io.*; J%8M+!`F
import java.net.*; 4CUoXs'
~&zrDj~FI
MCPVql`+`q
public class FileSplitterFetch extends Thread { [w0@7p"7
,r=9$i_
Iq76JJuCb
String sURL; //File URL hW^*b:v{
long nStartPos; //File Snippet Start Position YY!Lv:.7>
long nEndPos; //File Snippet End Position VnZRsFY<^
int nThreadID; //Thread's ID ].=~C"s,a
boolean bDownOver = false; //Downing is over #3b_#+,
boolean bStop = false; //Stop identical pQQN8Y~^Y
FileAccessI fileAccessI = null; //File Access interface <)hA?3J
{ylY"FA
wiwAdYEQ\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dC&OjBQ
{ 4trP*u,4
this.sURL = sURL; Ry$zF~[
this.nStartPos = nStart; s} I8:ufT
this.nEndPos = nEnd; W0zRV9"P
nThreadID = id; pUGFQ."\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W6e,S[J^FY
} |4$.mb.
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SG5GJCkc
public void run() [`F}<L."
{ S]}hh,A
while(nStartPos < nEndPos && !bStop) {D6p?TL+
{ (D\7EH\9,]
n@TK}?\UoR
Su4&qY
try{ )bd)noZi
URL url = new URL(sURL); QR ?JN\%?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -Kas9\VWEw
httpConnection.setRequestProperty("User-Agent","NetFox"); :4Gc'bR
String sProperty = "bytes="+nStartPos+"-"; qjcPJ
httpConnection.setRequestProperty("RANGE",sProperty); #[ H4`hZ
Utility.log(sProperty); &oz^dlw
Az+k8=?
u<g0oEs)
InputStream input = httpConnection.getInputStream(); r<%ua6@
//logResponseHead(httpConnection); H^VNw1.
lQ8h-Tz
h_( #U)z_3
byte[] b = new byte[1024]; /?ZO-]q
int nRead; BR*'SF\T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K@f@vyw]
{ d@0p<at>~
nStartPos += fileAccessI.write(b,0,nRead); L:.z FW,
//if(nThreadID == 1) Rudj"OGO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xJ$/#UdP
} ; ,vGw<|o
7J[DD5
.83{NF
Utility.log("Thread " + nThreadID + " is over!"); Cr7T=&L
bDownOver = true; wV604eO(
//nPos = fileAccessI.write (b,0,nRead); N4[`pXM6
} gNWTzz<[f>
catch(Exception e){e.printStackTrace ();} [%0{7pz}
} rN3qTp
} \&6^c=2=
@#j?Z7E|
#`HY"-7m_
//打印回应的头信息 9a6ij*#
public void logResponseHead(HttpURLConnection con) y6hb-: #1
{ qxQuXF>:#
for(int i=1;;i++) <Jf[N=
{ |3bCq(ZR\P
String header=con.getHeaderFieldKey(i); eT'Z;ZO
if(header!=null) *=2sXH1j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Uhw:XV@m
Utility.log(header+" : "+con.getHeaderField(header)); f`gs/R
else qk{+Y
break; @W1F4HYds
} m8T< x>
} n9%&HDl4
b2tUJ2p
5r)]o'?s
public void splitterStop() RPB%6z$
{ t:O"t G
bStop = true; KLBX2H2^0
} ( kKQs")
]aMeMhe-
<2V:tj)?P
} O a%ZlEUF
8Y,imj\(v
xU!eT'Y
/* \C}_l+nY
**FileAccess.java mm:g9j
*//文件访问(定位，写) ;ztt*py
package NetFox; (M-Wea!q
import java.io.*; ln2lFfz
%K[u
X{u\|e{
public class FileAccessI implements Serializable{ IA;'5IF
fEB&)mM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "g%=FH3e
RandomAccessFile oSavedFile; ED;rp9(
long nPos; YApm)O={
69?wZfj'
I^l\<1"]
public FileAccessI() throws IOException 9 S4bg7
{ $X_A74(
this("",0); KCl85Wi'
} KNG7$icG
NVX@1}
'JRYf;9c
public FileAccessI(String sName,long nPos) throws IOException >X_5o^s2s
{ m#,AD,s
oSavedFile = new RandomAccessFile(sName,"rw"); \|YIuzlO4
this.nPos = nPos; :V!F~
oSavedFile.seek(nPos); p9-s'F|@i
} ,<t)aZL,A;
Tl!}Rw~Pg
o JX4+uJ
public synchronized int write(byte[] b,int nStart,int nLen) UGP,/[XI
{ aCF=Og
int n = -1; _]t^F9l
try{ wZ%a:Z4TcM
oSavedFile.write(b,nStart,nLen); #oD;?Mi
n = nLen; $4:Se#nl
} He)!Ez\X
catch(IOException e) _Q9I W
{ Yv/T6z@
e.printStackTrace (); .z, ot|
} {fI"p;|
H(gETRh
045_0+r"@
return n; `LOW)|6r`
} sXwa`_{
F#)@ c
'\% Kd+k
} E}g)q;0v|2
Q;?rqi ,
y#{v\h Cz
/* _KJ!C!
**SiteInfoBean.java n+57# pS7
*/ NHQi_U
package NetFox; rK[;wD<
&7r73~TXm
Bp-e< :
public class SiteInfoBean { dT7!+)s5-
;R([w4[~
3_ ZlZ_Tq
private String sSiteURL; //Site's URL 2C AR2V|
private String sFilePath; //Saved File's Path .$ X|96~$
private String sFileName; //Saved File's Name WRp0.
private int nSplitter; //Count of Splited Downloading File dUH+7.\
KP&$Sl
=`ECM7
public SiteInfoBean() |@BX*r
{//nSplitter的缺省值为5 [=TD)o>W(p
//default value of nSplitter is 5 vMzBp#MT
this("","","",5); i:|e#$x
} _>E=.$
@y2cC6+'t
oc"7|YG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8l*h\p:Q
{ FGzn|I
sSiteURL= sURL; X@ S~D7|ja
sFilePath = sPath; q.bxnta"
sFileName = sName; $kBcnk
this.nSplitter = nSpiltter; <~zPt&C]V
V-9\@'gc
.dsB\C
} v Q51-.g
no(or5UJ
C@WdPjxj
public String getSSiteURL() o8X? 1
{ ?&-$Zog
return sSiteURL; 6[,7g&C
} @77+K:9I7
p$}/~5b}4
>U)>~SQf
public void setSSiteURL(String value) P~;1adi3
{ "hnvND4=
sSiteURL = value; /\MkH\zg
} 8?1MnjhX10
6^)eW+
{_4`0J`3
public String getSFilePath() >en\:pJn)'
{ On0,#i=
return sFilePath; / 5/mx
} [)?yH3
ft1V1 c
Q<Qd*v&-
public void setSFilePath(String value) _p'u!.a?!
{ FXul u6"SX
sFilePath = value; O1!YHo
} _ glB<r$
=>XjChM
yO` |X
public String getSFileName() >T)tAZ?WK
{ s Fx0
return sFileName; 9)>+r6t
} ECk3Da
]xGpN ]u
eo~b]D
public void setSFileName(String value) /!%?I#K{Wq
{ tn;{r
sFileName = value; /VD[:sU7
} 2BiFP||
(+SL1O P
:j? MEeu
public int getNSplitter() 6xFchdMG{m
{ Dutc#?bT
return nSplitter; I|wC`VgB
} B`YD>oCN
CwD=nT5`
Vjd(Z
public void setNSplitter(int nCount) s4j]kH
{ ?6UjD5NkX
nSplitter = nCount; 4";NT;_q5
} Vha,rIi
} )q`.tsR>
w3#0kl
0\Tp/Ph
/* bB)$=7\
**Utility.java >7r%k,`
*/ #/5eQTBD
package NetFox; vdigw.=z
,w f6gmh8
V.ETuS;
public class Utility { Et y?/
eVd:C8q
G#ELQ/Q
public Utility() _St":9'uU
{ kek/C`7
NLu[<u U*
JXHf$k
} P/xEn_*v
BF 0#G2`h>
//线程睡眠 (b.4&P"0
public static void sleep(int nSecond) "MK2QIo
{ $)~:H-
try{ ,& wd
Thread.sleep(nSecond); 9Vl}f^Gn
} {|@}xrB
catch(Exception e) x3sX=jIW_
{ ,f@j4*)
e.printStackTrace (); ' 6)Yf}I
} O{\%{XrW
} W>qu~ak?x
j3H_g^
//日志 yo8mfH_,
public static void log(String sMsg) s>W :vV@
{ *U}-Y*
System.err.println(sMsg); eSHsE3}h
} {|<yZ,,p
7rYBFSp
5V~vND* s
public static void log(int sMsg) 'h^Ya?g
{ L)4~:f)B
System.err.println(sMsg); @t0T+T3
} l-Ha*>gX[j
} UFLx'VXd
`PUxR8y
HCCq9us
/* MPKrr
**TestMethod.java /r2S1"(q
*/ !X||ds
package NetFox; >?_}NZ,y
6(x53y__
:pNS$g[
public class TestMethod { 7yXJ\(6R_
sAPQbTSM
}/#*opcv
public TestMethod() T1R~^x1
{ ///xx/weblogic60b2_win.exe &,3s2,1U(
try{ ,CN(;z)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NpCQ4K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z9MR"!0
SiteFileFetch fileFetch = new SiteFileFetch(bean); KFRf5^%
fileFetch.start(); m9\"B3sr
} t: oQHhO?
catch(Exception e){e.printStackTrace ();} 8'_MCx(
=v'Aub
q317~z_nl
} M,X)rM}Q
}_F:]lI*R
GY.iCub
public static void main(String[] args) &}0QnO_mj
{ |@d}O8
new TestMethod(); =HJ7tele
} Nr+~3:3
} OCJt5#e~A
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