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)); WwKpZ67$R
} ,&O&h2=
for(int i=0;i<nEndPos.length-1;i++) HyQ(9cn|
{ La7}zXx
nEndPos = nStartPos[i+1]; >N~jlr|
} ja{x}n*5
nEndPos[nEndPos.length-1] = nFileLength; m60hTJ?N)
} :Xx7':5
} 0!axAvBV
YAi@EvzCVy
54s90
//启动子线程 _$}@hD*R~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gV5mERKs
for(int i=0;i<nStartPos.length;i++) ^@'zQa
{ dleLX%P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zJ8jJFL+Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pBu}c<
nStartPos,nEndPos,i); ypA 9WF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kZ^wc .
fileSplitterFetch.start(); --`W1!jI@
} ej(w{vl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P^BSl7cT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sY}0PB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #g Rns
nEndPos = " + nFileLength); VhgcvS@V
// fileSplitterFetch[nPos.length-1].start(); +sd':vE
Tkh?F5l
EiA_9%<
//等待子线程结束 lqoVfj'6M
//int count = 0; /w*HxtwFmD
//是否结束while循环 iA"H*0
boolean breakWhile = false; Ao *{#z
'EU|w,GL}
sR$/z9w
while(!bStop) s*kSl:T@O
{ Aacj?
write_nPos(); ~?lmkfy
Utility.sleep(500); z&|sks7
breakWhile = true; yMb.~A^$J
\#'m([<e
niCq`!
for(int i=0;i<nStartPos.length;i++) %bTXu1
{ # 9ZO1\
if(!fileSplitterFetch.bDownOver) t(- 5l
{ rf2-owWN
breakWhile = false; :\#/T,K"
break; 1FRpcE
} g\?7M1~
} ur/:aI
if(breakWhile) $K~ t'wr
break; @0%^\Qf2
O#b%&s"o
y]%Io]!d
//count++; |+Ub3<b[]
//if(count>4) ::k/hP9.^
// siteStop(); fh}j)*K8
} (w, Gv-S
-Wl79lE
&28%~&L
System.err.println("文件下载结束！"); G~\=:d=^,`
} j1P#({z[
catch(Exception e){e.printStackTrace ();} 2NqO,B|R
} dmE.yVI"O
gA DF
Lc13PTz>>g
//获得文件长度 Nc[u?-
public long getFileSize() }JBLzk5|
{ 5]@"f/
int nFileLength = -1; 1bJrEXHXy
try{ A{QA0X!p
URL url = new URL(siteInfoBean.getSSiteURL()); AU^5N3%j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fop'm))C8
httpConnection.setRequestProperty("User-Agent","NetFox"); Z"'tJ3Y.~
<>6DPHg~
y[sO0u\
int responseCode=httpConnection.getResponseCode(); 7 a_99?J
if(responseCode>=400) =G%L:m*
{ $2gZpO|
processErrorCode(responseCode); 4BAG GD2
return -2; //-2 represent access is error \#)w$O
} H~r":A'"*
d,caOE8N
$y+Bril5W
String sHeader; )Fh5*UC
]Br6!U4~
;*XH[>I
for(int i=1;;i++) $[DSe~
{ 8P3"$2q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *b+~@o
//Utility.log(in.readLine()); I9;,qd%<T
sHeader=httpConnection.getHeaderFieldKey(i); /p_#8}Uh
if(sHeader!=null) /L? ia
{ El#"vIg(\
if(sHeader.equals("Content-Length")) B`<K]ut
{ &+zS4)UK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r:Rk!z*
break; |KLCO'x
} EgT?Hvx:
} e.jbFSnA
else TQg~I/
break; |QB[f*y5
} A 2Rp
} _/`H<@B_U
catch(IOException e){e.printStackTrace ();} 6@; P
catch(Exception e){e.printStackTrace ();} ==)q{e5
%d"d<pvx
>qC,IQ'
Utility.log(nFileLength); #9ZHt5T=$
?,0 a#lG
\olYv!f
return nFileLength; qaZQ1<e
} pDV8B/{
{f:%+h
@pkQ2OM 2
//保存下载信息（文件指针位置） /U5!]7&gB
private void write_nPos() T_/ n#e
{ Uon^z?0A
try{ s2*~n_B
output = new DataOutputStream(new FileOutputStream(tmpFile)); GW;O35 m
output.writeInt(nStartPos.length); e> -fI_+b
for(int i=0;i<nStartPos.length;i++) d !=AS
{ G3_HX<|f*
// output.writeLong(nPos); )]M,OMYq-
output.writeLong(fileSplitterFetch.nStartPos); <<l1zEf@
output.writeLong(fileSplitterFetch.nEndPos); OH/!Ky\@
} ^2)<H7p
output.close(); V18A|]k
} RBOg;EJ
catch(IOException e){e.printStackTrace ();} :^H2D=z@
catch(Exception e){e.printStackTrace ();} &\$~
} ~6Pv5DKq
{U"=}j(
+LwwI*;b
//读取保存的下载信息（文件指针位置） ^bk:g}o
private void read_nPos() ( we)0AxF'
{ oFL7dL
try{ BDfJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r%\%tz'`j
int nCount = input.readInt(); uF<}zFS
nStartPos = new long[nCount]; t0.71(
nEndPos = new long[nCount]; ^2C \--=;
for(int i=0;i<nStartPos.length;i++) -]<<}@NF
{ R@~=z5X(Q
nStartPos = input.readLong(); s((c@)M
nEndPos = input.readLong(); i62GZeE
} #Oi{7~
input.close(); "6q@}sz!
} |'qvq/#^
catch(IOException e){e.printStackTrace ();} sT'j36Nc<,
catch(Exception e){e.printStackTrace ();} bJoP@s
} crQ_@@X?<
ftxy]NLF
d.$0X/0
private void processErrorCode(int nErrorCode) j:E3c\a
{ |.;*,bb|3
System.err.println("Error Code : " + nErrorCode); H5Bh?mw2
} s"5wnp6pW
BU.O[?@64
W:>XXUU
//停止文件下载 XaF;IS@A
public void siteStop() u0F{.fe
{ m:6*4_!
bStop = true; K57u87=*X?
for(int i=0;i<nStartPos.length;i++) _%G;^ b
fileSplitterFetch.splitterStop(); 4s6,`-
[ji')PCAi;
'x6rU"e$J
} k)R~o b
} ny:/a
//负责部分文件的抓取 \aN7[>R.Q
**FileSplitterFetch.java f7/M_sx
*/ rvuasr~
package NetFox; Pk>S;KT.
KAgxIz!^-1
t;V^OGflv
import java.io.*; qOv`&%txW
import java.net.*; 57KrDxE}
KM?w{ ~9
~r_2V$sC2
public class FileSplitterFetch extends Thread { E24j(>
a4n5i.;
OIDP#K
String sURL; //File URL "U/yq
long nStartPos; //File Snippet Start Position aNBwb9X
long nEndPos; //File Snippet End Position ~OWpk)Vq
int nThreadID; //Thread's ID 45k.U$<|
boolean bDownOver = false; //Downing is over >qBJK)LHOv
boolean bStop = false; //Stop identical ]=PkgOJD
FileAccessI fileAccessI = null; //File Access interface Hb/8X !=
-A@/cS%p
1@i/N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4'TssRot@h
{ WL?qulC}h1
this.sURL = sURL; #r/5!*3
this.nStartPos = nStart; OZA^L;#>
this.nEndPos = nEnd; $z`l{F4eMf
nThreadID = id; vR&b2G7o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Lrmhr3 w5
} X]o"4#CQIX
[N#4H3GM8
+,cd$,18
public void run() ?L0|$#Iw
{ z,bK.KFSs
while(nStartPos < nEndPos && !bStop) Z1Qv>@u
{ m>RtKCtP
WZTAXOw
E]}_hZU
try{ !^o{}*]Pi
URL url = new URL(sURL); |3^U\r^zo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zXU g(xu
httpConnection.setRequestProperty("User-Agent","NetFox"); @AM11v\:
String sProperty = "bytes="+nStartPos+"-"; `<kB/T
httpConnection.setRequestProperty("RANGE",sProperty); {pA&Q{ ^
Utility.log(sProperty); 1xu~@v60
3 qJ00A
7&9w_iCkV
InputStream input = httpConnection.getInputStream(); {3.n!7+
//logResponseHead(httpConnection); o)>iHzR</
UNK.39
V%z?wDC
byte[] b = new byte[1024]; |f/Uzd ~
int nRead; T "hjL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A7,%'.k
{ JU.!<
nStartPos += fileAccessI.write(b,0,nRead); .YWkFTlZ+
//if(nThreadID == 1) pwkTe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g"k4Z
} c*]f#yr?
99(@O,*(Y
5423Ky<
Utility.log("Thread " + nThreadID + " is over!"); Xs# _AX
bDownOver = true; <h;_:
//nPos = fileAccessI.write (b,0,nRead); jm@,Ihz=wI
} QnP?j&
catch(Exception e){e.printStackTrace ();} 4w#2m>.
} \#WWJh"W
} 9D Nd} rXO
Kn<+Au_]L
ck%YEMs
//打印回应的头信息 J3~%9MCJ
public void logResponseHead(HttpURLConnection con) K~2sX>l
{ dJ/gc"7aO
for(int i=1;;i++) 9bM kP2w>
{ 97$Q?a8S@
String header=con.getHeaderFieldKey(i); -*Rf [|Z
if(header!=null) MnZljB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F\^8k/0
Utility.log(header+" : "+con.getHeaderField(header)); 2~l7WW+lx,
else dP+wcl4
break; 9P)!v.,T/
} de)4)EzUP
} dP(.l}O
9<&M~(dwT4
('Qq"cn#
public void splitterStop() ]jC{o,?s
{ Dr:M~r'6
bStop = true; Yj*T'<e
} c"-X:m"
:Yn.Wv-
F8dr-"G
} [@5cYeW3.
24k]X`/n
mXyN{`q=
/* 4x(m.u@
**FileAccess.java 1^*ogMe
*//文件访问(定位，写) ZOcpF1y
package NetFox; |>.MH
import java.io.*; Hg<aU*o;
7M7Lj0Y)L
ZS4dW_*[
public class FileAccessI implements Serializable{ Q~qM;l\i
A[^#8evaK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yP"}(!~m
RandomAccessFile oSavedFile; G+Z ,ic
long nPos; Dy,MQIM|!
=X^a
aJf3rHX
public FileAccessI() throws IOException `h'l"3l
{ LKp;sV
this("",0); u"V,/1++\
} ^67}&O^1 ,
*#b e
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public FileAccessI(String sName,long nPos) throws IOException dm[cl~[ Q
{ )Sb-e(sl
oSavedFile = new RandomAccessFile(sName,"rw"); YVa,?&i=N
this.nPos = nPos; "qF/7`e[
oSavedFile.seek(nPos); VgIk'.
} 97\K]Tr
89^g$ ac
aVK,(j9u
public synchronized int write(byte[] b,int nStart,int nLen) RV_I&HD!
{ e+-#/i*
int n = -1; qpjZ-[UC
try{ %q3`k#?<
oSavedFile.write(b,nStart,nLen); gBhX=2%
n = nLen; X>yDj]*4P
} ZCj1Cz]"l<
catch(IOException e) g[1>|Ax`'
{ f4\$<g/~
e.printStackTrace (); 8Cp@k=
} yc?L OW0
c`\/]
p*42 @1,
return n; 4V4S5V
} 7r'_p$
`r-Jy{!y4
EC8Z. Uu
} 8g!79q\c4
N8At N\e
[(_,\:L${
/* =cS5f#0
**SiteInfoBean.java I50LysM
*/ dR.?Kv(,E
package NetFox; \RR` F .7
L-E?1qhP>
y[.lfW?)
public class SiteInfoBean { Xwo+iZ(a
8CRbo24"s
1ow,'FztPt
private String sSiteURL; //Site's URL = FV12(U
private String sFilePath; //Saved File's Path zn^7#$fC
private String sFileName; //Saved File's Name +C7E]0!r
private int nSplitter; //Count of Splited Downloading File CKZEX*mPC
[Z2[Iy
$dKfUlO
public SiteInfoBean() KJOb1MM
{//nSplitter的缺省值为5 )8g&lyT
//default value of nSplitter is 5 'D`lVUB
this("","","",5); +u=VO#IA#
} *&IvEu
VT4>6u}
F%$q]J[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tlD^"eq4:
{ *q=\e9
sSiteURL= sURL; s?m_zJh
sFilePath = sPath; xg, 9~f[
sFileName = sName; uwI"V|g%a&
this.nSplitter = nSpiltter; mD% qDKI
:TP4f ?FA
,7s+-sRG
} ./3/3&6
oXht$Q
RAu(FJ
public String getSSiteURL() HU/4K7e`
{ v)O].Hd
return sSiteURL; >6&Rytcc]
} R"HV|Dm|m
:d35?[
;:oJFI#;
public void setSSiteURL(String value) Wf8@B#^{
{ @|"K"j#
sSiteURL = value; &g90q
} Ws2?sn#x
PB"=\>]`N
QA^FP8!j
public String getSFilePath() gV9bt~
{ zmD7]?|
return sFilePath; %wru)
} A9]&w
KwaxNb5
o-&0_Zq_
public void setSFilePath(String value) i9qIaG/
{ (U$;0`
sFilePath = value; N<4 nb
} 9^H.[t
ADOA&r[
*PFQ
public String getSFileName() AFBWiuwI3
{ lcEK&AtK
return sFileName; GNuIcy
} |Bi7:w
-CFy
^^!G{*F
public void setSFileName(String value) pQc-}o"
{ ci2Z_JA+
sFileName = value; Ylu\]pr9|C
} nIL67&
T+RC#&>
yDZm)|<.
public int getNSplitter() 8_Uhh5[
{ (xTGt",_Jo
return nSplitter; $'eY-U8q
} ]n"RPktx
+hispU3ia
O x`K7$)
public void setNSplitter(int nCount) `x>6Wk1
{ n`w]?bL
nSplitter = nCount; Svo\+S
} uF}B:53A
} a%kvC#B
<z#Fj`2{
1\aTA,
/* ;34p [RT
**Utility.java zv/dj04>
*/ zAklS 7L
package NetFox; UA~ 4O Q]
v)gMNzt
id8QagJ
public class Utility { n=$ne2/
),Yk53G6c
uHmvHA~/c8
public Utility() O(=9&PRi
{ 2T(+VeMQ=
@+p(%
/)K;XtcN
} ]63! Wc
$YY{|8@kjv
//线程睡眠 ~QPTs1Vk8
public static void sleep(int nSecond) sSGXd=":
{ #$2/<
try{ }#4Ek8nFR
Thread.sleep(nSecond); J#i7'9g
} ]e"!ZR?XJ
catch(Exception e) , .;0xyc
{ W+"^!p|
e.printStackTrace (); Lr8|S
} -oUNK}>
} Y[R>?w
Z^4+ 88
//日志 VEIct{
public static void log(String sMsg) w3>11bE
{ &^HVuYa.0
System.err.println(sMsg); % C2Vga#
} sb8bCEm-\
oCI\yp@a
U{pg y#/
public static void log(int sMsg) ceCO*m~
{ fvi0gE@bd
System.err.println(sMsg); vZ srlHb
} CqZHs 9+e&
} [v*q%Mi_
G?XA",AC
3Os0<1@H
/* SvvNk
**TestMethod.java 'OP0#`6`
*/ ]Z6? m
package NetFox; oxL<\4)WJ
+YW;63"o
l,l6j";ohd
public class TestMethod { =4SXntU!e
VR&dy|5BO
.f-=gZ* *
public TestMethod() Ny/eYF#
{ ///xx/weblogic60b2_win.exe wi jO2F
try{ M")/6PH8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w"dKOdY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ku]?"{Xx
SiteFileFetch fileFetch = new SiteFileFetch(bean); :0 n+RL*5
fileFetch.start(); 0^uUt-
} {R@V
catch(Exception e){e.printStackTrace ();} h{ix$Xn~
\$Wpt#V
\({'Xo >(
} (Y7zaAG]
AL3iNkEa
Mkk.8AjC|
public static void main(String[] args) kVKAG\F
{ a <?~1pWtc
new TestMethod(); Bh cp=#
} 76<mP*5
} ,z/aT6M?H
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