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)); o(54 A['
} n?OMfx
for(int i=0;i<nEndPos.length-1;i++) *HV_$^)=
{ X04LAYY_u
nEndPos = nStartPos[i+1]; %K\B)HR
} dly -mPmP
nEndPos[nEndPos.length-1] = nFileLength; mz<,nR\
} XHgW9;M!
} a|t{1]^w`
K`X'Hg#_P2
N&k\X]U
//启动子线程 n'pJl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jYAm}_?No
for(int i=0;i<nStartPos.length;i++) ZWuNl!l>
{ INk|NEX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Snmv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3My}u>
nStartPos,nEndPos,i); j<Pw0?~s6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [N[4\W!!
fileSplitterFetch.start(); UjJ&P)
} p_n$}z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L)7{_s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~qL/P 5*+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w-km qh
nEndPos = " + nFileLength); ^zqQ8{oV
// fileSplitterFetch[nPos.length-1].start(); Kt]vTn7!9
k:j?8o3
`]19}GK~xo
//等待子线程结束 HtE^7i*_
//int count = 0; 438r]f?0|{
//是否结束while循环 9'|k@i:
boolean breakWhile = false; oGeV!hD
rB(Q)N
,:-^O#
while(!bStop) dW5r]D[Cx
{ >N`, 3;Z
write_nPos(); 0%\fm W j
Utility.sleep(500); }4c$_
breakWhile = true; +",`Mb
16z WmJH
9"B;o
for(int i=0;i<nStartPos.length;i++) U~7{q >
{ lQ[JA[
if(!fileSplitterFetch.bDownOver) K'"s9b8
{ Mjl,/-0 w
breakWhile = false; qnd] UUA^
break; _Y6Ezh.
} eo!+UFZbY
} %M^Q{` :5
if(breakWhile) Ym -U{a
break; =/ !A
0@u{(m
~_ovQ4@
//count++; }p)a7xn}
//if(count>4) yVPFH~1@\
// siteStop(); WoSKN7*
} hD,^mru
nddCp~NX
0T$`;~
System.err.println("文件下载结束！"); \b)P4aL
} q9^.f9-
catch(Exception e){e.printStackTrace ();} <0l:B;3
} 8)`
b-c6.aKf|
h"2^` )!u
//获得文件长度 JiA1yt
public long getFileSize() >: @\SU
{ kY4h-oZ
int nFileLength = -1; [P)](8nR[
try{ >A6PH*x
URL url = new URL(siteInfoBean.getSSiteURL()); %2G3+T8*x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %md9ou`
httpConnection.setRequestProperty("User-Agent","NetFox"); % 1<@p%y/
j6 _w2
[a^<2V!vMn
int responseCode=httpConnection.getResponseCode(); 1&=2"
if(responseCode>=400) rX`fjS*C
{ ZiH4s|
processErrorCode(responseCode); bhZ5-wo4%
return -2; //-2 represent access is error |NjyO>@Pa
} wlP% U
cIuCuh0I`
pFo,@M
String sHeader; $K|2k7
`\BBdQ#bH
{+9t!'
for(int i=1;;i++) Fk`6 q
{ :}v:=ck
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c Ct5m
//Utility.log(in.readLine()); hGUQdTNP
sHeader=httpConnection.getHeaderFieldKey(i); un,W{*s8*
if(sHeader!=null) R3BK\kf&
{ 1_n5:
if(sHeader.equals("Content-Length")) ) I.uqG
{ -fK_F6_\]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $7Lcn9?G
break; GL&rT&
} p1ER<_fp
} kY~yA2*G
else L{c\7
break; TjctK [db@
} KZ [:o,jp>
} >4T7DMy
catch(IOException e){e.printStackTrace ();} MF::At[4
catch(Exception e){e.printStackTrace ();} Zk gj_
2+LvlS)C
pl 1CEoe
Utility.log(nFileLength); +k
vZSwX@0
WMoRosL74
return nFileLength; # kmI#W"^
} ljh,%#95=
?3iN)*Ut
6y@o[=m
//保存下载信息（文件指针位置） DsiyN:o'+
private void write_nPos() q1%xk=8
{ Sa6YqOel@
try{ "9H#pj -
output = new DataOutputStream(new FileOutputStream(tmpFile)); KH[Oqd
output.writeInt(nStartPos.length); J8`vk#5
for(int i=0;i<nStartPos.length;i++) V}G;oz&>)
{ .ityudT<
// output.writeLong(nPos); &gvX<X4e
output.writeLong(fileSplitterFetch.nStartPos); mgEZiAV?
output.writeLong(fileSplitterFetch.nEndPos); 4-xg+*()
} Cz4l
output.close(); r*ry8QA
} OgyHX>}bH
catch(IOException e){e.printStackTrace ();} D_I_=0qNd
catch(Exception e){e.printStackTrace ();} /9C>{29x!
} LS1}j WU!
gHU0Pr9'
qI\B;&hr(
//读取保存的下载信息（文件指针位置） V ;M'd@
private void read_nPos() {Hxziyv~Y(
{ YccD^w[`B
try{ P-\T BS_O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }/.b@`Dh;
int nCount = input.readInt(); Y{m1\s/o
nStartPos = new long[nCount]; \,b_8^
nEndPos = new long[nCount]; [-Mfgw]i
for(int i=0;i<nStartPos.length;i++) (Yc}V
{ wQ9fPOm
nStartPos = input.readLong(); mY]R~:
nEndPos = input.readLong(); 9t0NO-a
} n11eJEtm
input.close(); 9uY$@7qH
} > bSQ}kXe
catch(IOException e){e.printStackTrace ();} %XWb|-=
catch(Exception e){e.printStackTrace ();} 6q^.Pg-Y
} sX=_|<[
lem\P_V)
zQ,ymfT
private void processErrorCode(int nErrorCode) {UEZ:a
{ j}DG +M
System.err.println("Error Code : " + nErrorCode); p4wXsOQ}
} q^kOyA.
'\Hh
;jpsH?3g
//停止文件下载 KZTT2KsYl
public void siteStop() SNf*2~uq)
{ B976{;QvXV
bStop = true; sBu- \P#
for(int i=0;i<nStartPos.length;i++) A!!W\Jt
fileSplitterFetch.splitterStop(); yi3Cd@t({{
h{M.+I$}C
@{UtS2L
} 9.$k^|~
} &]HY:
//负责部分文件的抓取 62%=%XD
**FileSplitterFetch.java tdB<
*/ ?e!mv}B_
package NetFox; ]W 6!Xw)[
}Z}4_/E
pWXoJ0N
import java.io.*; aUX.4#|%
import java.net.*; C)`y<O
elm]e2)F
*H,vqs\}y
public class FileSplitterFetch extends Thread { {%3sj"suB
D[ (A`!)
+&hd3
String sURL; //File URL ,v+~vXO&\
long nStartPos; //File Snippet Start Position _kT$/k
long nEndPos; //File Snippet End Position IHtNaN )
int nThreadID; //Thread's ID c2<JS:!*
boolean bDownOver = false; //Downing is over D>Dch0{H,:
boolean bStop = false; //Stop identical ^iaG>rvA
FileAccessI fileAccessI = null; //File Access interface qY$/i#
G4eY}3F7,4
8DP] C9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =7uxzg/%Tj
{ .#y.:Pb|e
this.sURL = sURL; z>X<Di&x)
this.nStartPos = nStart; BliL1"".
this.nEndPos = nEnd; Qyoly"b@
nThreadID = id; c)OQ_3xOs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PF?tEw_WB
} juQQ
^X/[x]UOT@
E)w^odwMU
public void run() A~Ov(
{ Ov=^}T4zl
while(nStartPos < nEndPos && !bStop) "]C$"JR
{ =tE7XC3X_
\d#|n u
t LZ4<wc
try{ &(Ot(.
URL url = new URL(sURL); 2-*zevPiG=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jx8?x#}
httpConnection.setRequestProperty("User-Agent","NetFox"); 4:p+C-gs
String sProperty = "bytes="+nStartPos+"-"; |+Fko8-
httpConnection.setRequestProperty("RANGE",sProperty); w8df-]r
Utility.log(sProperty); UfnjhHu
HqpwQ
R4Vi*H
InputStream input = httpConnection.getInputStream(); {m/h3hjFa
//logResponseHead(httpConnection); ]N+(SU
A\7qPfpG
LD~/*
byte[] b = new byte[1024]; 8QN#PaY
int nRead; =)GhrWeVi4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i?&g;_n^
{ H#luG_)
nStartPos += fileAccessI.write(b,0,nRead); Ht Z3n"2
//if(nThreadID == 1) G'sEbw'[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s<t*g]0`/
} P=%'2BQ{{
AF}6O(C~
!Z*2X ^
Utility.log("Thread " + nThreadID + " is over!"); Z;6v`;[
bDownOver = true; <g|\]\C|
//nPos = fileAccessI.write (b,0,nRead); kFlq@['U
} [80L|?, *
catch(Exception e){e.printStackTrace ();} P<@V
} e-dpk^-
} O%.c%)4Xo
"[ 091<
`|\z#Et
//打印回应的头信息 ;LM,<QJ
public void logResponseHead(HttpURLConnection con) 7LM?<lp]
{ HH+$rrTT
for(int i=1;;i++) ?,J'3nZ'
{ CVp`G"W:
String header=con.getHeaderFieldKey(i); m4.IaBn/
if(header!=null) kCWaji_x%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <TL!iM
Utility.log(header+" : "+con.getHeaderField(header)); l H@hV
else 9K\A4F}
break; H53dy*wb$
} B=mk@gX,G
} *TEgV
n-P)X<\
%B&y^mZv*\
public void splitterStop() U=4tJb
{ ?n 9<PMo
bStop = true; 3(De> gs$
} Q,# )
zCZ]`
Dl2`b">u
} Bn 5]{Df
=N5~iMorD-
lj{Jw.t
/* Ps@a@d"83
**FileAccess.java [/B$cH
*//文件访问(定位，写) df=G}M(
package NetFox; 'w^Md
import java.io.*; z3V[ Vi
"w#jC~J<W
biy1!r
public class FileAccessI implements Serializable{ 66G$5
8cV3VapF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Flrpk`4
RandomAccessFile oSavedFile; HB}!Lf#*P
long nPos; .""?k[f5Q
dX4"o?KD>
2E Ufd\
public FileAccessI() throws IOException 8Z{e/wnVF
{ uTgvMkO
this("",0); n2NxO0
} K'6dlwn).
}IM*Vsk
\t6k(5J
public FileAccessI(String sName,long nPos) throws IOException tnv @`xBn
{ x]~{#pH@<
oSavedFile = new RandomAccessFile(sName,"rw"); IUt/V^
this.nPos = nPos; W$g<nhLK
oSavedFile.seek(nPos); Vz(O=w=
} ZK1H%&P=R
zJhG`iWFw
yMdE[/+3
public synchronized int write(byte[] b,int nStart,int nLen) h[|c?\E z
{ q2o`.f+I
int n = -1; 2$)xpET
try{ r5h+_&v,M
oSavedFile.write(b,nStart,nLen); 8T&.8r
n = nLen; [8F1rZ&
} D"x;/I
catch(IOException e) f@3?kM(
{ ?C%mwW3pc
e.printStackTrace (); PBXRey7>D
} yfq Vx$YL
Pz+2(Z
:qfP>Ok
return n; UMcQqV+vT
} 8F?6Aq1B
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l[Hgh,
} ~N<zv({lG
5crd.1@^
0X.(BRI~6p
/* 6:Fb>|]*PY
**SiteInfoBean.java !'y9/
*/ 2pKkg>/S
package NetFox; :gD=F&V
rb"J{^
=;hz,+
public class SiteInfoBean { it Byw1/
(n4\$LdP-
3`%]3qd}
private String sSiteURL; //Site's URL ljr?Z,R4
private String sFilePath; //Saved File's Path %rU8^'Gu
private String sFileName; //Saved File's Name #@rvoi
private int nSplitter; //Count of Splited Downloading File >S<`ri'5_
{5%u G2g
8dgi"/[3
public SiteInfoBean() :eL{&&6
{//nSplitter的缺省值为5 `%%/`Qpj;
//default value of nSplitter is 5 Pdq}~um3{
this("","","",5); /2%646
} })v`` +
)=~OP>7B
<_o).hE{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IE^xk@
{ e}xx4mYo
sSiteURL= sURL; .paKV"LJ
sFilePath = sPath; V8Lp%*(3
sFileName = sName; $,@PY5r
this.nSplitter = nSpiltter; pTQ70V3
r |H 1Yy
;rH<
} xaPaK-
LqZsH0C
`>i8$q%
public String getSSiteURL() @N tiT,3k
{ %<^IAMkp
return sSiteURL; kH.e"e
} ZOAHM1ci
&nKb<o
xtWwz}^8]
public void setSSiteURL(String value) CyR1.|!@
{ kYW>o}J|
sSiteURL = value; *n"{]tj^>
} zwLJ|>
q(Q$lRj/I-
yH9(ru
public String getSFilePath() n+'gVEBA
{ |~+i=y
return sFilePath; Oq`CKf
} f/?uosS
6Z}8"VJr {
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public void setSFilePath(String value) efT@A}sV
{ _~QiQDq
sFilePath = value; 8q}955Nl
} vtA%^~0
=._V$:a6o
~W>3EJghR,
public String getSFileName() M:PEY*4H
{ HQy:,_f@
return sFileName; cF2!By3M
} q6]T;)U&
762c`aP_(
_ SuW86
public void setSFileName(String value) :{g;J
{ &1 BACKu
sFileName = value; `K%f"by
} a'Vz|SG
?LwBF;Y
H(QbH)S$6
public int getNSplitter() K Y=$RO
{ ^b;3Jj
return nSplitter; 0XSMby?t`
} ` P,-NVB
"9^OT
(zmLMG(R
public void setNSplitter(int nCount) : Yb_
{ =$wQA
nSplitter = nCount; K!<3|d
} 83i;:cn
} Jv8JCu"eky
)wM881_!
)w_hbU_Pb&
/* A!:R1tTR;S
**Utility.java y),yks?iv
*/ zMg(\8
package NetFox; ;"9$LHH*
nu6p{_M
B<Zm'hdX
public class Utility { 2{6%+>jB
w;wgh`ur
CZzgPId%x
public Utility() f;`7}7C
{ 2Kmnt(>
riu_^!"Z_
~p!=w#/
} !^x;4@Ejm
P-_2IZiz
//线程睡眠 _qf$dGqc
public static void sleep(int nSecond) A=f)ntH~
{ Y(<(!TJ-
try{ ]}Jb'(gMO4
Thread.sleep(nSecond); z=j,-d%9
} o]<@E uG
catch(Exception e) {5NE jUu{j
{ Jwtt&" c0.
e.printStackTrace (); B;A< pNT
} C9j3|]nyL
} kTfE*We9
Ywo=w:'
//日志 uE ^uP@d
public static void log(String sMsg) Htm;N2$d
{ :m[HUh
System.err.println(sMsg); (RBB0CE
} wlEmy.)H
2~y<l
= tY%k!R
public static void log(int sMsg) BmI'XB3'P
{ er0y~
System.err.println(sMsg); 'h#>@v> }
} k fY0u
} [2.;gZj
Blox~=cW
5`FPv4
/* mum4Uj
**TestMethod.java p7p6~;P
*/ G<FB:?|
package NetFox; iTVepYv4m
C5^9D
vm.%)F#@
public class TestMethod { ehV}}1>O
U1=]iG<%
Ol)M0u
public TestMethod() Fvr$K*u
{ ///xx/weblogic60b2_win.exe S^7u`-
try{ ^5Ob(FvU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wqF_hs(O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~0YRWM;
SiteFileFetch fileFetch = new SiteFileFetch(bean); `OHdo$Y9
fileFetch.start(); 'EO"0,
} 2&0#'Tb
catch(Exception e){e.printStackTrace ();} +wE>h>?;
l:14uWu|
ZJ%iiY
} 0I}c|V'P
(L,>P`CR6
[u;>b?[{
public static void main(String[] args) o(@^V!}V
{ V?r(;x
new TestMethod(); $|o[l.q2
} |!xqkmX
} OP98sd&T
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