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)); e?KzT5j:
} qsYg%Z
for(int i=0;i<nEndPos.length-1;i++) DyUS^iz~o
{ H=mFc@fh
nEndPos = nStartPos[i+1]; p?4,YV|#
} LMLrH.
nEndPos[nEndPos.length-1] = nFileLength; 1c*;Lr.K
} zNg[%{mz
} ~,x4cOdR#
okO\A^F
]\/"-Y#4Q
//启动子线程 4K|O?MUNS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \GZ|fmYn
for(int i=0;i<nStartPos.length;i++) $3cZS
{ 8zho\'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VU+=b+B~m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w8`B}Dr23
nStartPos,nEndPos,i); jcRe),
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :OA;vp~$x
fileSplitterFetch.start(); G(bl)p^
} FgMQ=O2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xZVZYvC,t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'oUTY *
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fx:4d$>;
nEndPos = " + nFileLength); <00=bZzX
// fileSplitterFetch[nPos.length-1].start(); f @Vd'k<
2dDhO
*qFl&*h}
//等待子线程结束 #S[Y}-]T
//int count = 0; 4hkyq>c}
//是否结束while循环 02-% B~oP
boolean breakWhile = false; j_z@VT}y
E,Xl8rC
S.pXo'}
while(!bStop) }-Jo9dNs
{ Z=]ujlD
write_nPos(); ; FHnu|
Utility.sleep(500); 7t/Y5Qf
breakWhile = true; h\+8eeIl
@S6@pMo,
Z1]4:
for(int i=0;i<nStartPos.length;i++) 7R,;/3wWjG
{ #oN}DP
if(!fileSplitterFetch.bDownOver) A.~wgJDO
{ $"?$r
breakWhile = false; ST,+]p3L(
break; .0MY$0s
} 8EBd`kiq
} [I7=]X
if(breakWhile) 0:c3aq&u
break; gLK0L%"5
9~y:K$NO
>'jkL5l
//count++; 0IBQE
//if(count>4) UUF]45t>
// siteStop(); v@{VQVx
} e7plL^^`
B;2#Sa.
=,X*40=
System.err.println("文件下载结束！"); KDj/S-S
} J7t) H_S{
catch(Exception e){e.printStackTrace ();} Zqb*-1Qw"*
} x{/-&`F
Vt:\llsin
G"".;}AV
//获得文件长度 j3u!lZ}U
public long getFileSize() *w/N>:V0p
{ NLUiNfCR
int nFileLength = -1; Iz>\qC}
try{ Y=y 0`?K
URL url = new URL(siteInfoBean.getSSiteURL()); .:e#!~Ki
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p(9[*0.};
httpConnection.setRequestProperty("User-Agent","NetFox"); qggRS)a
IYa(B+nB)
e*d lGK3l
int responseCode=httpConnection.getResponseCode(); dJlK'zK
if(responseCode>=400) U8@P/Z9
{ MPF({Pnx7
processErrorCode(responseCode); x6^FpNgQ
return -2; //-2 represent access is error qxYCT$1
} s4Vju/
}vg|05L
uO1^nK
String sHeader; 7p>T6jK)
A$L:,b(
\tCK7sBn
for(int i=1;;i++) RJ{J~-q{
{ F*-'8~T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GB,ub*|
//Utility.log(in.readLine()); ID,os_ T=
sHeader=httpConnection.getHeaderFieldKey(i); rje;Bf
if(sHeader!=null) lA`-"
{ ]cMZ7V^
if(sHeader.equals("Content-Length")) =5uhIU0O
{ *xpPD\{k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yh).1Q-D
break; nP|ah~ q
} ngk:q5Tp
} {wO.nOB
else <vu~EY0.
break; `,4YPjk^
} o@C|*TXN
} +U?73cYN
catch(IOException e){e.printStackTrace ();} n8D'fvY
catch(Exception e){e.printStackTrace ();} a.ijc>K
GoPMWbI7
@gQ?cU7
Utility.log(nFileLength); \x5>H:\Y
ZT`" {#L
fd62m]X
return nFileLength; "Nz"|-3Irv
} 1`l(H4
MYR\W*B'b
u=E &jL5U
//保存下载信息（文件指针位置） Ec}9R3 m
private void write_nPos() #MbY+[Y@v
{ #jO2Zu2`}
try{ UQWv)
output = new DataOutputStream(new FileOutputStream(tmpFile)); $#wi2Ve=6b
output.writeInt(nStartPos.length); O"_QDl<ya
for(int i=0;i<nStartPos.length;i++) gV*4{d`
{ XXQC`%-]<i
// output.writeLong(nPos); $"#M:V@
output.writeLong(fileSplitterFetch.nStartPos); +aqQa~}r
output.writeLong(fileSplitterFetch.nEndPos); [$fB]7A
} =PnNett}a
output.close(); dkSd Y+Q
} )]Sf|@K]
catch(IOException e){e.printStackTrace ();} v[?gM.SF
catch(Exception e){e.printStackTrace ();} 9<"F3F0|
} #W8c)gkG9
f/Z-dM\e
vq@"y%C4
//读取保存的下载信息（文件指针位置） "u{ymJ]t
private void read_nPos() >!c Ff$2'
{ PE[5oH
try{ _ -,[U{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e$mVA}>Ybp
int nCount = input.readInt(); ?Qts2kae#
nStartPos = new long[nCount]; W!TTfj
nEndPos = new long[nCount]; `}8)P#
for(int i=0;i<nStartPos.length;i++) L$jii
{ `];ne]xM
nStartPos = input.readLong(); '8I=Tn
nEndPos = input.readLong(); ")NQwT}
} )a+bH</'
input.close(); Z$35`:x&h
} "kucFf f
catch(IOException e){e.printStackTrace ();} 'z+Pa^)v
catch(Exception e){e.printStackTrace ();} FE#|5;q.
} ONc#d'-L
]]5(:>l
F'_z$,X6
private void processErrorCode(int nErrorCode) 0 eOdE+
{ 'SIc2H
System.err.println("Error Code : " + nErrorCode); ")fgQ3XZ
} K5(T7S
x26 sH5
7mb5z/N
//停止文件下载 4&6cDig7*2
public void siteStop() P)ne^_
{ -'i[/{
bStop = true; 6S(`Bw8h
for(int i=0;i<nStartPos.length;i++) 5Iv"
fileSplitterFetch.splitterStop(); ]0{,P !
=E~_F>SD
'n?"f|G
} w}29#F\]R
} HS1{4/
//负责部分文件的抓取 kC'm |Y@T
**FileSplitterFetch.java jank<Q&w
*/ j\.e6&5%SS
package NetFox; N0ZD+
:rvBx"
/&!o]fU1C
import java.io.*; TNcMrbWA
import java.net.*; 9s*UJIL
paxZlA o
eE{ 2{C
public class FileSplitterFetch extends Thread { Y2+YmP*z`
foI:`]2"*
V0gu0+u~R
String sURL; //File URL W5&KmA
long nStartPos; //File Snippet Start Position lI5>d(6p
long nEndPos; //File Snippet End Position rhN"#?
int nThreadID; //Thread's ID lB|.TCbW
boolean bDownOver = false; //Downing is over :[Ie0[H/M
boolean bStop = false; //Stop identical &(20*Vn,O
FileAccessI fileAccessI = null; //File Access interface mUiJ@
WkoYkkuzj
pU u')y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >Q)S-4iR
{ g G|4+' t
this.sURL = sURL; zXd#kw;
this.nStartPos = nStart; YIYuqtnSJ
this.nEndPos = nEnd; e"2x!(&n(
nThreadID = id; u5,vchZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \/r]Ra
} =e6!U5 f
E7]a#
(. ,{x)H
public void run() >SD?MW1E
{ v\XO?UEJ2
while(nStartPos < nEndPos && !bStop) 1ay{uU!EL
{ L-e6^%eU
R7x*/?
}5?|iUH|
try{ b+71`aD0
URL url = new URL(sURL); ck8Qs08
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TG.\C8;vFh
httpConnection.setRequestProperty("User-Agent","NetFox"); WVL\|y728s
String sProperty = "bytes="+nStartPos+"-"; ,w_C~XN$t
httpConnection.setRequestProperty("RANGE",sProperty); g;y*F;0@
Utility.log(sProperty); cP0(Q+i7
6%T_;"hb
o1Wf#Zq
InputStream input = httpConnection.getInputStream(); -}Rh+n`
//logResponseHead(httpConnection); 'gk^NAG2^E
H]Gj$P=k
hud'@O"R+
byte[] b = new byte[1024]; e4cWi
int nRead; 0#F<JsO|u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M5]$w]Ny9
{ `P;uPQDzZ3
nStartPos += fileAccessI.write(b,0,nRead); qp]sVY
//if(nThreadID == 1) 4WQ 96|F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uz7V2r%]
} #YLI"/Kn
FFf ~Vmw
d,t'e?
Utility.log("Thread " + nThreadID + " is over!"); S,C/l1s
bDownOver = true; Zb~G&. 2g
//nPos = fileAccessI.write (b,0,nRead); V}4u1oG
} g^:7mG6C
catch(Exception e){e.printStackTrace ();} Zor Q2>
} !(N,tZ
} LeMo")dk\
jL~. =QD
8;Df/%
//打印回应的头信息 bj 0-72V
public void logResponseHead(HttpURLConnection con) W-vEh
{ X""}]@B9z
for(int i=1;;i++) 6^nxw>-
{ 4eS(dPI0
String header=con.getHeaderFieldKey(i); L4Si0 K
if(header!=null) |C\XU5}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'S;l"
Utility.log(header+" : "+con.getHeaderField(header)); $60]RCu
else L$f:D2Ei
break; ?yvjX90
} cX48?srG
} Z`@< O%
Pv3 e*I((
-O[9{`i]
public void splitterStop() W; ?'
{ kL%o9=R1
bStop = true; w Yr M2X@
} ':T6m=yv
TfFH!1^+
%>:d5"&Lbs
} m?<5-"hz
k#/%#rQM
P.]O8r
/* D-\z'gS
**FileAccess.java ,SoqVboRl
*//文件访问(定位，写) x% Eu.jj
package NetFox; p87VJ}
import java.io.*; <(2,@_~@r
'FGf#l<
|'12Kv]#Xa
public class FileAccessI implements Serializable{ </7?puVR
0'^zIL#.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V?Ye^-29
RandomAccessFile oSavedFile; K#'{Ko
long nPos; 8'Bik
hjY)W;
=uIeur
public FileAccessI() throws IOException Pb@9<NXm'
{ bA3pDt).p
this("",0); gA:N>w&<X
} Twr<MXa
~,P."
#5W-*?H
public FileAccessI(String sName,long nPos) throws IOException ik|iAWy
{ z8n]6FDiE
oSavedFile = new RandomAccessFile(sName,"rw"); =Ev*Q[
this.nPos = nPos; q|wwfPez7
oSavedFile.seek(nPos); R9V v*F]m@
} v8o{3wJ
(]p,Z<f
,;-55|o\V
public synchronized int write(byte[] b,int nStart,int nLen) ]abox%U=%
{ _l!TcH+e
int n = -1; `Ui|T
try{ /YH5s=
oSavedFile.write(b,nStart,nLen); ih/MW_t=m=
n = nLen; =lqGt.x
} j`kw2(
catch(IOException e) L;k9}HWpP
{ 06S-3bis
e.printStackTrace (); N6_<[`
} A!j6JY.w
gdyP,zMD7
tV,Y38e
return n; `O|PP3S
} or1D 6*'
&B5@\Hd;
)6:nJ"j#
} o w<.Dh
QC*> qo
q!+m, !M
/* t9B]V
**SiteInfoBean.java cA{zyq26
*/ L|[0&u!
package NetFox; AT4G]pT
`FL!L59nz
RtVG6'Y
public class SiteInfoBean { hZ@Wl6FG;
Fi^Q]9.@{
3mnq=.<(w
private String sSiteURL; //Site's URL ?1u2P$d
private String sFilePath; //Saved File's Path ]MXeWS(
private String sFileName; //Saved File's Name Z6I^HG{:
private int nSplitter; //Count of Splited Downloading File ~&Gw[Nd1
wx|eO[14
o {bwWk7v6
public SiteInfoBean() Q(Dp116
{//nSplitter的缺省值为5 L0HkmaH
//default value of nSplitter is 5 { f@k2^
this("","","",5); s'/ g:aJ
} }+8w
OJ:iQ
A12#v,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pe_iA_
{ A<zSh}eh6
sSiteURL= sURL; =c,m)\u/8
sFilePath = sPath; Ph*tZrd*#
sFileName = sName; kK[m=rTx1$
this.nSplitter = nSpiltter; 8UyYN$7V
3+/{}rv
0oFRcU
} O67.DEu^
vUXas*s4
<e 'S'
public String getSSiteURL() b^Xq(q>5
{ HJ2r~KIw
return sSiteURL; P]4C/UDS-~
} OJL?[<I
/M;A)z
MR@*09zP(?
public void setSSiteURL(String value) {-(B
{ =gb.%a{R
sSiteURL = value; Ol9'ZB|R
} pZ,P_?
C1@6r%YD
<-:gaA`KM
public String getSFilePath() %usy`4 2
{ a0oM KGW:
return sFilePath; 'K=n}}&:
} (bk~,n_
TrHz(no
H *gF>1
public void setSFilePath(String value) G#&R/Tc5N
{ >d&_e[j
sFilePath = value; 0N~AQu
} gZ*8F|sg
Jm|eZDp
.OHjn|
public String getSFileName() {VPF2JFB[
{ Gmi w(T
return sFileName; p<\yp<g
} `4& GumG
OE(Z)|LF
D<zgs2Ex
public void setSFileName(String value) 3sf+uoV
{ >900O4
sFileName = value; !'()QtvC<
} P%v7(bqL4+
e{~s\G8g
VQ/<MY C
public int getNSplitter() |.x |BJ
{ ;=IGl:
return nSplitter; zice0({iJ
} fD#VI
piE9qXn
I|?zSFa
public void setNSplitter(int nCount) 5sD\4g)HK
{ _N5$>2
nSplitter = nCount; C%8jWc
} ?\C7.of
} #TLqo(/
C<GS._V&
lZ5 lmsCU
/* mJaWzR
**Utility.java }];8v+M
*/ +j._NRXRH
package NetFox; o:<gJzg
,[rh7_
t'bzhPQO)f
public class Utility { H1H+TTZr
CY&Z*JI"'B
P%8zxU;
public Utility() 7tgn"wK
{ cNzn2-qv
R&13P&:g
Hf ]aA_:
} $0C1';=^}
8}FZ1h2 4
//线程睡眠 $okGqu8z.O
public static void sleep(int nSecond) "=0#pH1o
{ Y4Hi<JWo
try{ n%lY7.z8d
Thread.sleep(nSecond); _u$X.5Q;
} b$kCyOg
catch(Exception e) ?d)I!x,;;
{ J+3PUfg>@R
e.printStackTrace (); =6Dz<Lq
} Z[Gs/D
} E"D+CD0
ITa8*Myj
//日志 4@D 8{?$~Q
public static void log(String sMsg) N-fGc?E
{ \e%H5Wx
System.err.println(sMsg); \vVGfG?6
} v:c_q]z#B
hm=E~wv'L
x j6-~<
public static void log(int sMsg) _@[M0t}g_
{ $~xY6"_}!!
System.err.println(sMsg); w:l/B '%]Y
} 3+gp_7L
} &h.E B
^NB@wuf7
E\2|
/* )J&1uMp{
**TestMethod.java FI1R7A
*/ q(0V#kKC
package NetFox; (B@:0}>
H tIl;E
Fv \yhR
public class TestMethod { -EV_=a8[y
\hpD
GU99!.$
public TestMethod() =p9d4smbn
{ ///xx/weblogic60b2_win.exe xy>~15
try{ Zvd^<SP<?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;0Yeo"-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5I,5da
SiteFileFetch fileFetch = new SiteFileFetch(bean); Np>[mNmga
fileFetch.start(); RkVU^N"
} P+!j[X^
catch(Exception e){e.printStackTrace ();} &K@2kq,
%zx=rn(K
&?\ h[3
} LJK<Xen
ngM>Tzirt
@[M5$,"
public static void main(String[] args) &]gw[ `
{ v=15pW
new TestMethod(); nlaJ
} E5.3wOE
} LyM"
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