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)); %Ts6M,Fpp
} QEe\1>1"&
for(int i=0;i<nEndPos.length-1;i++) 6;02_C]\o
{ $*035f
nEndPos = nStartPos[i+1]; `CWI%V
} Ue>;h9^
nEndPos[nEndPos.length-1] = nFileLength; ~nQv yM!$
} t:DZow
} +:hZ,G?>
{bxTODt@
}klET
//启动子线程 =l %
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; As$:V<Z
for(int i=0;i<nStartPos.length;i++) 0w0\TWz*
{ i'GBj,:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q~[@(+zP5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p)5j~Nl
nStartPos,nEndPos,i); W| z djb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Na*7|
fileSplitterFetch.start(); i8F^ N=
} kZ&|.q1zki
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z/#&c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v"y0D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 82S?@%}#J
nEndPos = " + nFileLength); FT*OF 3
// fileSplitterFetch[nPos.length-1].start(); ,_STt)
{XT3M{`rWL
^sLnKAN
//等待子线程结束 :L~{Q>o
//int count = 0; Q\pTyNAYn
//是否结束while循环 =Kq/EDe
boolean breakWhile = false; }ze,6T*z
cQ= "3M)~r
6}Se$XMl
while(!bStop) <Yzk]98W5.
{ ,G";ny[$
write_nPos(); \7W4)>At-
Utility.sleep(500); {u3eel
breakWhile = true; lzJ[`i.
8VbHZ9Q
AS 5\X.%L*
for(int i=0;i<nStartPos.length;i++) X2X.&^
{ 5H (CP
if(!fileSplitterFetch.bDownOver) zh5$$*\
{ J^}w,r*=
breakWhile = false; |'w_5?|4
break; K4]42#
} 8<,b5
} PNm WZW*
if(breakWhile) wA@y B"
break; c4]/{!4 Q
$$UMc-Pq
q|*}>=NX
//count++; jwm2ZJW
//if(count>4) h/I'9&J>*
// siteStop(); I! s&m%s
} ^tWt"GgC
-8sm^A>C
u/`jb2eEU:
System.err.println("文件下载结束！"); yc./:t1at>
} 3kAmRU
catch(Exception e){e.printStackTrace ();} ?^F*M#%?
} m!{}Y]FZn
I)wjTTM5
c\X0*GX
//获得文件长度 'dE G\?v9
public long getFileSize() q+A^JjzT
{ ?vHow$
int nFileLength = -1; BUH~aV
try{ KmuE#Ia
URL url = new URL(siteInfoBean.getSSiteURL()); ~Wh}W((L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G~,K$z/-l
httpConnection.setRequestProperty("User-Agent","NetFox"); (~YFm"S
=5NM =K
R|7yhsJq,
int responseCode=httpConnection.getResponseCode(); ( K5w0
if(responseCode>=400) I\NiA>c
{ v&BKl
processErrorCode(responseCode); ye-o'%{
return -2; //-2 represent access is error 0_Gi1)
} jy=dB-&
rgQ6/3}qc
'b#`)w@/=
String sHeader; 6`sOhVD
Y2&>;ym!
)&G uZ
for(int i=1;;i++) bFivHms
{ x/nlIoT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f1cQ*#2~
//Utility.log(in.readLine()); %s.hqr,I
sHeader=httpConnection.getHeaderFieldKey(i); g+5{&YD
if(sHeader!=null) zzf;3S?
{ Y{].%xM5
if(sHeader.equals("Content-Length")) {`Ekv/XWa
{ em^|E73
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pdcP;.
break; ]Y#$!fIx
} Ri$wt.b
} `;[j`v8O
else JCjQR`)
break; uZsm=('ww
} UlBg6
} 8&15kA
catch(IOException e){e.printStackTrace ();} . &dh7`l
catch(Exception e){e.printStackTrace ();} C4Pi6.wf
# 2As-9
vn n4
Utility.log(nFileLength); _xgF?#
;^5d^-T
.&:GOD
return nFileLength; GA19=gow
} +xqPyR
hFORs.L&G
OiB*,TWV
//保存下载信息（文件指针位置） &!I^m
private void write_nPos() 7U#`^Q}
{ f_`gUMf
try{ )9~1XiS,
output = new DataOutputStream(new FileOutputStream(tmpFile)); OrXx0Hn
output.writeInt(nStartPos.length); 7%p[n;-o&
for(int i=0;i<nStartPos.length;i++) i ! wzID
{ =^.f)
// output.writeLong(nPos); nSH A,c
output.writeLong(fileSplitterFetch.nStartPos); [al,UO
output.writeLong(fileSplitterFetch.nEndPos); #"}Z'|X*
} s: c
output.close(); yZf+*j/a7
} (<ybst6+I
catch(IOException e){e.printStackTrace ();} ?b',kN,(
catch(Exception e){e.printStackTrace ();} az7<@vSXi
} O.7Q*^_
neQ2k=ao
1jdv<\U
//读取保存的下载信息（文件指针位置） qaBjV6loy
private void read_nPos() Wsb=SM7;
{ 5oz[Njq4
try{ ()=u#y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0sjw`<ic
int nCount = input.readInt(); zV)Ob0M7U
nStartPos = new long[nCount]; }s;W{Q
nEndPos = new long[nCount]; ># FO0R
for(int i=0;i<nStartPos.length;i++) Lp\89tB>
{ &]VCZQL
nStartPos = input.readLong(); vkE[Ur>
nEndPos = input.readLong(); 3zJbb3e
} ZN)a}\]
input.close(); r>+Hwj0>
} O=os ,'"
catch(IOException e){e.printStackTrace ();} kc&>l(
catch(Exception e){e.printStackTrace ();} RulZh2C
} F{*S}&q*)o
'L#qR)t
du2q6"
private void processErrorCode(int nErrorCode) @;>TmLs
{ uVoM2n?D%^
System.err.println("Error Code : " + nErrorCode); 5MJ`B:He+
} :0BaEqX
846j<fE
pm<zw-
//停止文件下载 Wx}+Vq<q
public void siteStop() *#j+,q!X
{ ~8'4/wh+8
bStop = true; ,RFcR[ak
for(int i=0;i<nStartPos.length;i++) lhm=(7Y
fileSplitterFetch.splitterStop(); wI+oG
c1j)
=re1xR!E5
} YH`/;H=$G/
} Gy36{*
//负责部分文件的抓取 CFJ F}aW
**FileSplitterFetch.java zn5
*/ \XR%pC
package NetFox; KK-9[S-
Dx/!^L02
pyK|zvr-r
import java.io.*; ua(y! Im
import java.net.*; A:3bL: ;t
VNx|nP&
'>(R'g42n
public class FileSplitterFetch extends Thread { Mf0g)X}1
T:Dp+m!\{
'tK5s>gv<
String sURL; //File URL se](hu~w
long nStartPos; //File Snippet Start Position ;czMsHu0X
long nEndPos; //File Snippet End Position pfW0)V1t
int nThreadID; //Thread's ID 1 O+4A[cr
boolean bDownOver = false; //Downing is over =Haqr*PDx
boolean bStop = false; //Stop identical 3=xb%Upw
FileAccessI fileAccessI = null; //File Access interface bu"R2~sb
TRG(W^<F
W(9fCDO;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ToIvyeFr
{ .fxI)
this.sURL = sURL; CQfrAk4mu
this.nStartPos = nStart; -ecP@,
this.nEndPos = nEnd; 6L~@jg~0A[
nThreadID = id; _+K[1P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *a Y`[,4#$
} UJkg|eu
#3maT*JY
)AOD~T4s7
public void run() !Y_"q^5GG'
{ TDg#O!DUF
while(nStartPos < nEndPos && !bStop) R}4o{l6
{ 42LlR 0
}x4,a6^
-}k'a{sj=
try{ lpkg(J#&
URL url = new URL(sURL); 0j%@P[zQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZjLzS]\a
httpConnection.setRequestProperty("User-Agent","NetFox"); LH..8nfl
String sProperty = "bytes="+nStartPos+"-"; e47JLW&b
httpConnection.setRequestProperty("RANGE",sProperty); >jAr9Blz]
Utility.log(sProperty); QZk:G+$
+v%V1lf^~
Ky`rf}cI>
InputStream input = httpConnection.getInputStream(); +=%13cA*U
//logResponseHead(httpConnection); }AG$E}~/
ZjY_AbD
=flgKRKk.r
byte[] b = new byte[1024]; ~,yHE3B\G
int nRead; B+|E|8"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p8y_uNQE
{ 1QM*oj:
nStartPos += fileAccessI.write(b,0,nRead); J=>?D@K
//if(nThreadID == 1) J=67As
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /B"h#v-o
} 94r8DkI
.EVy?-
k%#`{#ni
Utility.log("Thread " + nThreadID + " is over!"); O!='U!X@P
bDownOver = true; xbrxh-gV
//nPos = fileAccessI.write (b,0,nRead); BR\%aU$u
} +NPk9jn
catch(Exception e){e.printStackTrace ();} 35Nwx<
} (+>~6SE
} sd\>|N?'
W<TW6_*e
+4ax~fuU
//打印回应的头信息 V ?3>hQtB
public void logResponseHead(HttpURLConnection con) a_I!2w<I
{ a8aEZ724
for(int i=1;;i++) qVC_K/w 7
{ &V1N a1`
String header=con.getHeaderFieldKey(i); S{j|("W"[
if(header!=null) H V<|eL #
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a>`\^>G4
Utility.log(header+" : "+con.getHeaderField(header)); [8.ufpZ
else "|`8mNC
break; K|];fd U
} +Tc4+q!
} "5e~19
Z$0r+phQk=
?*E Y~'I
public void splitterStop() 7P9n. [
{ 1Nw&Z0MI
bStop = true; I"@X~Y7}
} bv0B
-@i)2J_WP
N+l~r]: &
} 0.O pgv2K
AL! ^1hCF
y4)M,+O5
/* />q=qkdq0
**FileAccess.java :w(J=0Lt
*//文件访问(定位，写) /dhx+K~
package NetFox; Pca~V>Hd
import java.io.*; ;6t>!2I>C
;_K+b,
$-"AMZ899
public class FileAccessI implements Serializable{ :ORCsl6-
sF]v$kq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i9k7rEW^
RandomAccessFile oSavedFile; y#HD1SZ
long nPos; %0INtq
0m)["g4
<1&kCfE&
public FileAccessI() throws IOException ~X5yHf3
{ 28SlFu?
this("",0); F/ 2@%,2n
} F}0QocD
1O45M/5\o
2*n2!7jZ*
public FileAccessI(String sName,long nPos) throws IOException - t4"BD
{ :q~qRRmjBe
oSavedFile = new RandomAccessFile(sName,"rw"); KpC)A5u6
this.nPos = nPos; \^;Gv%E
oSavedFile.seek(nPos); w>; :mf
} +@]1!|@(
'LFHZ&-
m0]LY-t
public synchronized int write(byte[] b,int nStart,int nLen) FFbMG:>:
{ <.$<d
int n = -1; dJ?VN!B0
try{ Y+iC/pd
oSavedFile.write(b,nStart,nLen); :tdx:
n = nLen; cZ|D!1%
} J=*y>Zt-b
catch(IOException e) 3{Ze>yFE
{ OnH>g"
e.printStackTrace (); p1v:X?
} 0-0 )E&2
#"ayq,GC<
KU-z;}9s
return n; A/{pG#if]3
} IG`~^-}7lR
N ED`GU
Cd'P
} ce2d)FG}e
s7I*=}{g0.
,p1 (0i
/* & /-@R|
**SiteInfoBean.java Qat%<;P2
*/ FvG9PPd
package NetFox; "x9xJ
z:u`W#Rf
$2]1 3j
public class SiteInfoBean { MGc=TQ.
@EfCNOy
Rt7}e09HV
private String sSiteURL; //Site's URL *Vfas|3hZI
private String sFilePath; //Saved File's Path z$ysp!
private String sFileName; //Saved File's Name KyXgw
private int nSplitter; //Count of Splited Downloading File :m8ED[9b
KrMIJA4>
dwrc"GK!o
public SiteInfoBean() .~v~~VL1NS
{//nSplitter的缺省值为5 T 6QnCmB4
//default value of nSplitter is 5 >]:R{1h
this("","","",5); qqw6p j
} /T#<g:
x)"=*Jj
6i.'S5.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6$ IXER
{ t vk^L3=<
sSiteURL= sURL; JsnavI6
sFilePath = sPath; bIp;$ZHy`K
sFileName = sName; ^+`vh0TPQ
this.nSplitter = nSpiltter; t)cG_+rJ
G]P4[#5
c::x.B"w
} Lom%eoH)
32~Tf,
e"r}I!.
public String getSSiteURL() eoEb\zJ
{ ujz %0Mq;
return sSiteURL; + W@r p#
} Z6D4VZVF
<g*rTqT'
M|n)LyL
public void setSSiteURL(String value) %M}zi'qQ?
{ 7IK<9i4O
sSiteURL = value; dZ%b|CUb
} q{U -kuui
te6[^_k
~;+i[Z&e
public String getSFilePath() .Z_U]_(
{ GbP!l;a
return sFilePath; l06 q1M 3
} `t6lnO
Efp=z=E
1/cb;:h>
public void setSFilePath(String value) Q~xR'G[N
{ 1'aS2vB9
sFilePath = value; xR_]^Get
} .z[+sy_
g!~j Wn?A
gKYn*
public String getSFileName() T{)!>)
{ "*7I~.7U(*
return sFileName; e\yj>tQJg
} 2$\f !6p
s|,]Nb=z/
ZM|>Va/X
public void setSFileName(String value) b%oma{I=.c
{ G x,D'H'
sFileName = value; 1c}'o*K_%
} +Og O<P
20fCWVw}?}
fLD9RZ8_
public int getNSplitter() M j5C0P(
{ s &.Z;X
return nSplitter; R=e`QMq
} Q'8v!/"}p{
?-i|f_`
kkJg/:g
public void setNSplitter(int nCount) jV<LmVcZY
{ rW`F|F%
nSplitter = nCount; UoLO#C0i
} \6lXsu;I.X
} x _2]G'
7Ru0>4B
,7QnZ=F
/* ]-}a{z
**Utility.java v,M2|x\r}
*/ t[Q^Xp
package NetFox; "q(&<+D@
;m5M:Z"
{'b8;x8h
public class Utility { WEsH@ [
|hdh4P$+|
yq<YGNy!
public Utility() QqwXFk
{ !3b%Q</M H
Wt`D
Ja (/ym^
} ScTqnY$v
'sA&Pm
//线程睡眠 z N t7DK
public static void sleep(int nSecond) /tUl(Fp J`
{ 4/h2_
try{ ]Yj>~k:K
Thread.sleep(nSecond); Gg!))I+
} jNyC%$
catch(Exception e) y&CUT:M6
{ 9.@(&
e.printStackTrace (); fC-^[Af)
} jqLyX
} RhJ<<T.2
D3K`b4YV
//日志 6 %=BYDF
public static void log(String sMsg) {10ms_s
{ tS9m8(Hr%Q
System.err.println(sMsg); 1y@-
} 7d<v\=J}
z=fag'fzM
1]<!Xuk^f
public static void log(int sMsg) 9F-k:hD |
{ W+eN%w5
System.err.println(sMsg); ;+jp,( 7
} oF>GWstTR
} E??%)q
e"2QV vB
FjydEV
/* zm"\D vN)
**TestMethod.java J{Ay(
*/ Cn55%:
package NetFox; \%C[l
yjr@v!o
m3WV<Cbz
public class TestMethod { {L=[1
P~ykC{nD
};j&)M
public TestMethod() aE%VH ;?
{ ///xx/weblogic60b2_win.exe H|Nw)*.
try{ "5YdmBy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LBE".+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k|_2aQ02
SiteFileFetch fileFetch = new SiteFileFetch(bean); "4`%NA
fileFetch.start(); |. 6@-h~8
} f@{C3E dd
catch(Exception e){e.printStackTrace ();} IF:M_
saT9%?4-
%C)JmaQ{9
} yRznP)
[s/@z*,M1
cDx^}N!
public static void main(String[] args) Wk|z\OR(
{ Chua>p!$g
new TestMethod(); ./ :86@O
} k$c j|-<
} gctaarB&
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