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)); Rh,a4n?W
} Kk\TW1w3
for(int i=0;i<nEndPos.length-1;i++) xa[)fk$6
{ oB$c-!&
nEndPos = nStartPos[i+1]; L:_GpZ_
} /iw$\F |8
nEndPos[nEndPos.length-1] = nFileLength; R^?9V=Y<T
} hCPyCq]
} R KXhD PA
yBl9a-2A
rX}FhBl5
//启动子线程 { u %xc"0y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %}}?Y`/W)
for(int i=0;i<nStartPos.length;i++) x+8%4]u`
{ 5rH?FQE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^r@,(r6w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `Fx+HIng,
nStartPos,nEndPos,i); H#/Hs#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;-Ki`x.oJ
fileSplitterFetch.start(); ~Z:)Y*
} ufn%sA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N#p%^GH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CxD=8X9m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^u:bgwP
nEndPos = " + nFileLength); _lBHZJ+
// fileSplitterFetch[nPos.length-1].start(); hlBMRx49
,}:}"cl
*_sSM+S
//等待子线程结束 dlRTxb^Y>u
//int count = 0; .x'?&7#(
//是否结束while循环 h7kn >q;
boolean breakWhile = false; Vj[hT~{f
1$)}EL
x8o/m$[,=u
while(!bStop) ?3y>K!D(A
{ ]NyN@9u@(
write_nPos(); Ke^9R-jP
Utility.sleep(500); #+Y%Bxf
breakWhile = true; Jbn^G7vH<6
&Lbh?C
#H]c/
for(int i=0;i<nStartPos.length;i++) 8/<+p? 3p>
{ `Jj q5:\&
if(!fileSplitterFetch.bDownOver) RqKkB8g
{ i<{:J -U|
breakWhile = false; fb[? sc
break; b#(X+I
} tTbfyI
} UCo`l~K)qg
if(breakWhile) Z]XjN@j"
break; ~7wLnB
wlFK#iK
&N*l?7(
//count++; i8A-h6E
//if(count>4) ;]l`Q,*OXb
// siteStop(); "^oU&]KQJ
} cI'su?
+y^'\KN
#x6EZnG
System.err.println("文件下载结束！"); ct@3]
} XzBlT( `w
catch(Exception e){e.printStackTrace ();} #sE:xIR
} E(_lm&,4+
84<zTmm
aA]wFZ
//获得文件长度 :W#?U yo
public long getFileSize() D `av9I
{ L;=3n[^x
int nFileLength = -1; >avkiT2
try{ X]_9g[V
URL url = new URL(siteInfoBean.getSSiteURL()); u{cb[M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xYY^tZIV
httpConnection.setRequestProperty("User-Agent","NetFox"); '=(D7F;
8Oa+,?<0x
@<yYMo7
int responseCode=httpConnection.getResponseCode(); .I]EP-
if(responseCode>=400) %<|cWYM="z
{ s_3a#I
processErrorCode(responseCode); 7NkMr8[}F
return -2; //-2 represent access is error LbuhKL}VN
} KB{IWu
Wf~PP;
VAp 1{
String sHeader; j_.tg7X
R5xV_;wD
CIVV"p`}
for(int i=1;;i++) oA8A @,-L
{ h!`KX2~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yQ!keGj
//Utility.log(in.readLine()); N|%X/UjZ2.
sHeader=httpConnection.getHeaderFieldKey(i); `7oYXk
if(sHeader!=null) /m4Y87
{ l{Et:W%|
if(sHeader.equals("Content-Length")) 8Vy/n^3)
{ "5v^6R9e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J&bMox
break; F_&H*kL L3
} )d>Dcne
} ,ZVhL* "
else }}l jVUpC%
break; s^k<r;'\
} .LGA0
} xyHv7u%*
catch(IOException e){e.printStackTrace ();} c9djBUAk&
catch(Exception e){e.printStackTrace ();} \wR\i^
bc;?O`I<
o*3\xg
Utility.log(nFileLength); kG5Uc83#G
"-\8Y>E
owwWm1@
return nFileLength; 5lyHg{iqD
} %~M#3Ywa
qfRrX"
.*Z#;3
//保存下载信息（文件指针位置） .EC~o
private void write_nPos() Y?-Ef sK
{ {"*_++|
try{ pb G5y7
output = new DataOutputStream(new FileOutputStream(tmpFile)); j=c< Lo`
output.writeInt(nStartPos.length); $W9dUR0
for(int i=0;i<nStartPos.length;i++) a*t>Ks'C
{ LYiIJAZ.
// output.writeLong(nPos); D~M*]&
output.writeLong(fileSplitterFetch.nStartPos); |pBvy1e4)
output.writeLong(fileSplitterFetch.nEndPos); t^2$ent
} :(4q\~
output.close(); !r9rTS]
} ?X Rl\V
catch(IOException e){e.printStackTrace ();} !}sF#
catch(Exception e){e.printStackTrace ();} R+2~%|{d
} ],{M``]q
24sQon
WXG0Z
//读取保存的下载信息（文件指针位置） s#(7D3Pr#
private void read_nPos() L* ScSxw
{ p.H`lbVY
try{ $j\jT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]=59_bkD:s
int nCount = input.readInt(); 5H,(\Xd
nStartPos = new long[nCount]; i^8w0H<-@v
nEndPos = new long[nCount]; /B|"<`-H
for(int i=0;i<nStartPos.length;i++) CAmIwAx6;
{ ff=RKKnN
nStartPos = input.readLong(); k5*Z@a
nEndPos = input.readLong(); A|GsbRuy
} ,c 0]r;u!
input.close(); _#uRKy<`N
} jUDE)~h
catch(IOException e){e.printStackTrace ();} %cJdVDW`L
catch(Exception e){e.printStackTrace ();} q29d=
} J4s`U/F
_Fe=:q
Qz"//=hC|H
private void processErrorCode(int nErrorCode) 0#ON}l)>
{ J(A+mYr{:
System.err.println("Error Code : " + nErrorCode); KFy|,@NI
} PZ#aq~>w
>U?#'e{qW
!)}D_9{
//停止文件下载 1:_}`x=hM
public void siteStop() D |fo:Xp,
{ c._!dq&#R
bStop = true; j,Qb'|f5
for(int i=0;i<nStartPos.length;i++) d,Oe3?][0p
fileSplitterFetch.splitterStop(); ~M1T @Mv
HGi%b5:<=M
t3C#$>
} q^7=/d8
} 9$}>O]
//负责部分文件的抓取 :XTxrYt28
**FileSplitterFetch.java &Aym@G|k?
*/ [E"3?p
package NetFox; nFe
Yv2L0bUo:
>h~>7i(A
import java.io.*; {hm-0Q
import java.net.*; *~w?@,}
JvaHH!>d/
]mjKF\
public class FileSplitterFetch extends Thread { .'4@Yp{=
A7eYKo q
[?(qhp!
String sURL; //File URL 2wgcVQ Awa
long nStartPos; //File Snippet Start Position 1_StgFu u
long nEndPos; //File Snippet End Position \&U"7gSL
int nThreadID; //Thread's ID bjN"H`Q
boolean bDownOver = false; //Downing is over vV*/"'>
boolean bStop = false; //Stop identical JeAyT48!M
FileAccessI fileAccessI = null; //File Access interface wRq f'
:c`djM^ll
XhN?E-WywQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {7q8@`Oa
{ r5+MjR
this.sURL = sURL; /Ao.b|mm
this.nStartPos = nStart; sDu&9+
this.nEndPos = nEnd; +vPCr&40
nThreadID = id; =#wE*6T9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T+FlN-iy)
} dEor+5}
zm4e+v-
m`b:#z
public void run() i98PlAq)B
{ Ct:c%D(L
while(nStartPos < nEndPos && !bStop) Tz7R:S.
{ 1{ ehnH
q!q=axfMD
w(ic$
try{ w;J#+ik
URL url = new URL(sURL); yA`,ns&n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KqNsCT+j
httpConnection.setRequestProperty("User-Agent","NetFox"); f917F.1I
String sProperty = "bytes="+nStartPos+"-"; k9c`[M
httpConnection.setRequestProperty("RANGE",sProperty); A-eCc#I
Utility.log(sProperty); |>-0q~
6+C]rEY/o
db3.X~Cn#s
InputStream input = httpConnection.getInputStream(); 'lgS)m
//logResponseHead(httpConnection); W;U<,g '
N'|9rB2e
ZJ[p7XP
byte[] b = new byte[1024]; "L9pFz</
int nRead; U]ZI_[\'U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \tdYTb.
{ '[bw7T
nStartPos += fileAccessI.write(b,0,nRead); "tj]mij2)G
//if(nThreadID == 1) [.;8GMW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); clM6R
} -&QpQ7q1
NIC.c3
9Dyy&$s
Utility.log("Thread " + nThreadID + " is over!"); q@Zeu\T,*#
bDownOver = true; nzU0=w}V
//nPos = fileAccessI.write (b,0,nRead); 59?$9}ob
} HLh]*tQG
catch(Exception e){e.printStackTrace ();} lvUWs
} ESe$6)P
} KnK\X>:
v,US4C|^3i
g=Nde2d?
//打印回应的头信息 ;3Q3!+%j
public void logResponseHead(HttpURLConnection con) c{jTCkzq
{ t /lU*
for(int i=1;;i++) pz.fZV
{ B""=&(Yu
String header=con.getHeaderFieldKey(i); AO8%!+"_
if(header!=null) T3-/+4$0v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1NK,:m
Utility.log(header+" : "+con.getHeaderField(header)); 3:b5#c?R-
else 4c.!^EiV
break; 0X%#9s~
} U{HBmSR
} `<% w4E
mrlhj8W?!
x![ut
public void splitterStop() f6#1sO4"
{ S^~ lQ|D
bStop = true; 4>]B8ZxH
} Qaiqx"x3
=DI/|^j{;
;]2d%Qt
} Nh6!h%
a3:1`c/~\
D5!I{hp"
/* |(9l_e|
**FileAccess.java Jz-RMX=
*//文件访问(定位，写) &3P"l.j
package NetFox; c2yZvi
import java.io.*; )N&95\u
; VQ:\fG
~vfPsaRh
public class FileAccessI implements Serializable{ 85+w\KuEY
,6wGdaMR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vGp`P
RandomAccessFile oSavedFile; PxJvE*6^H
long nPos; I&5cUj{GX-
:n oZ p:a
=Unu>p}2V
public FileAccessI() throws IOException _147d5
{ CW~c<,"
this("",0); j8ac8J,}c
} uecjR8\e
Z'c9xvy5
@u8kNXT;h
public FileAccessI(String sName,long nPos) throws IOException %v]-:5g'|
{ ' h|d-p\`9
oSavedFile = new RandomAccessFile(sName,"rw"); =%+xNOdN7?
this.nPos = nPos; L#/<y{
oSavedFile.seek(nPos); ,*;g+[Bhpl
} ~&+8m=
4TaHS!9
szy2"~hm
public synchronized int write(byte[] b,int nStart,int nLen) cUU"*bA#
{ 7i9wfc h$U
int n = -1; \}7xgQ>oV
try{ >+*lG>!z
oSavedFile.write(b,nStart,nLen); GUsJF;;V
n = nLen; .+-7 'ux
} <z{,@Z}
catch(IOException e) :tLMh08h
{ e`%<D[-
e.printStackTrace (); ZZW%6-B
} hj3wxH.}
iD:TKB_r
8{p#Nl?U1
return n; qWI8 >my11
} BU%gXr4Ra
Gk<6+.c~
4pFoSs?\
} "%+9p6/
\0^Je>-:U
!A"-9OS2
/* k i{8f
**SiteInfoBean.java }yM!o`90
*/ nkz^^q`5l7
package NetFox; %eE 6\f%g
t` zPx#])
'tq4-11xB
public class SiteInfoBean { AXpyia7nU
P? LpI`f
g<MCvC@
private String sSiteURL; //Site's URL aX35^K /
private String sFilePath; //Saved File's Path Mog!pmc{
private String sFileName; //Saved File's Name Y!_e,]GW
private int nSplitter; //Count of Splited Downloading File ~@K!>j
/U"3LX
O)}5`0@L
public SiteInfoBean() =2, iNn
{//nSplitter的缺省值为5 -2y>X`1Y
//default value of nSplitter is 5 5<|X++y}8)
this("","","",5); w'P!<JaZ
} h7>`:~
~01Fp;L/
mvGj !'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i8`0-
{ stlkt>9
sSiteURL= sURL; DX8pd5U
sFilePath = sPath; @%$<,$=
sFileName = sName; h,P#)^"
this.nSplitter = nSpiltter; {8J+Y}
UQ+!P<>w
zT jk^
} o$,e#q)8
GhY MO6Q4
l%MIna/Tp
public String getSSiteURL() R"[U<^
{ [!b=A:@
return sSiteURL; s;YuB#Z
} gJuA*^
%weG}gCM
RL1cx|
public void setSSiteURL(String value) 66Xo3o
{ Ea?u5$>gY"
sSiteURL = value; A$o?_
} &13#/
,c[f/sT\
^es/xt
public String getSFilePath() psE&Rx3)
{ !"N-To-c
return sFilePath; UWq[K&vQZ
} T&kr IZw
hdx"/.s
VeWvSIP,EQ
public void setSFilePath(String value) G^_fbrZjN
{ ;bes#|^F
sFilePath = value; @ykM98K
} I0C$
[V.#w|n
)nA fT0()0
public String getSFileName() Ct30EZ
{ zX ?@[OT
return sFileName; ~!TRR.
} #Up X
5<L+T
~>|o3&G{
public void setSFileName(String value) TTzvH;S
{ O{nM yB
sFileName = value; I]Jz[{~1
} @j?)uJ0Q
,.&y-?
jsnk*>j
public int getNSplitter() ayoqitXD?
{ 1A-ess\
return nSplitter; R3gg{hQ
} 8iwqy0<
tJ!s/|u(
NU$?BiB?R
public void setNSplitter(int nCount) UqaV9
{ 8!u8ZvbFG
nSplitter = nCount; mA>u6Rlc
} T_b$8GYfCY
} Q{+N{/tF
z\?cazQ
WEFvJ0]
/* lq\/E`fc`
**Utility.java UFY_.N~
*/ k874tD
package NetFox; x6={)tj
!`?*zf
[agp06 $D?
public class Utility { Q7@.WG5
o$+"{3svw?
x*2'I
public Utility() !/Wp0E'A
{ or{X{_X7
%>Y86>mVz
]S#m o
} h#!u"'JW
~]&,v|g&
//线程睡眠 l d4#jV ei
public static void sleep(int nSecond) -<Zs7(
{ S8$kxQg
try{ QvN=<V
Thread.sleep(nSecond); W_ hckq.
} #^~[\8v>
catch(Exception e) |T@\-8Ok
{ (:2,Rr1"
e.printStackTrace (); `cBV+00YS
} m?Qr)F_M
} 3>t^Xu~
,/>hWAx
//日志 ;.4A,7w#
public static void log(String sMsg) (( D*kd"
{ o:irwfArv
System.err.println(sMsg); ,3tcti~sZ
} A$]&j5nh|
\$] V#@F
,Bg)p_B
public static void log(int sMsg) |p"E0av
{ <Fa]k'<^)
System.err.println(sMsg); io{uN/!X_J
} E Z}c8b
} #- hYjE5
{2Jn#&Z29
D-<9kBZs
/* (d2|r)O
**TestMethod.java &hb:~>
*/ Ow\dk^\-G8
package NetFox; ZH<:YOQ
)|?s!rw +
*6trK`tx^
public class TestMethod { /X_g[*]?
`pzXh0}|
H=j&uv8
public TestMethod() DZI:zsf;5Q
{ ///xx/weblogic60b2_win.exe |3A/Og
try{ a*Oc:$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r)G^V&96
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TsB"<6@!AA
SiteFileFetch fileFetch = new SiteFileFetch(bean); "/&_B
fileFetch.start(); |*+f N8
} 2HemPth
catch(Exception e){e.printStackTrace ();} 8- U1Y
Qwm#6{5
D< h+r?
} hS}d vZa
}I1SC7gY
RS>;$O_(M
public static void main(String[] args) !F_BLHig
{ {T0f]]}Q
new TestMethod(); 6:v$g
} cJnAwIs_e`
} } :@s
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