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)); 1?6zsA%N
} pAZD>15l"
for(int i=0;i<nEndPos.length-1;i++) PcxCal4
{ Cp[{|U-?G
nEndPos = nStartPos[i+1]; X:3W9`s)*
} 6S`J7[
nEndPos[nEndPos.length-1] = nFileLength; ix.I)
} aJAQ G
} ' ];|
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YwYCXFQ|
//启动子线程 ^p@ #
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $0(~ID
for(int i=0;i<nStartPos.length;i++) vh29mzum
{ BRSOE U\=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i.~*G8!DM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qj$6/V|D
nStartPos,nEndPos,i); Imv]V6"D=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gk-g!v&
fileSplitterFetch.start(); RxeyMNd
} hoJ{C 0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O4l]Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ysHmi{V~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ggQBQ/ L
nEndPos = " + nFileLength); cq?&edjP
// fileSplitterFetch[nPos.length-1].start(); N51g<K
`fL81)!jI#
f>i" j
//等待子线程结束 /kK%}L_D
//int count = 0; B'@a36
//是否结束while循环 v +$3Z5
boolean breakWhile = false; krt8yAkG
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@0v%5@
while(!bStop) <"}Gvi
{ 94Hs.S)
write_nPos(); da,;IE{1u
Utility.sleep(500); 76'vsg
breakWhile = true; li`4&<WGC
i!tF{'*%#
-_4ZT^.Lna
for(int i=0;i<nStartPos.length;i++) P.j0Xlof
{ )9PP3"I
if(!fileSplitterFetch.bDownOver) 0}:wM':G
{ 8B|qNf `Yi
breakWhile = false; ,'FdUq)i
break; uyfH;9L5$
} \/ 9s<
} rNl`w.
if(breakWhile) /4Q^L>a
break; )]W|i9
Qgel^"t]i
@71n{9
//count++; >&`S$1 o
//if(count>4) H:x{qS4Si
// siteStop(); w4"4(SR.
} :VB{@ED
i_KAD U&mP
:RqTbE4B
System.err.println("文件下载结束！"); 1638U1
} |+|q`SwJ
catch(Exception e){e.printStackTrace ();} 13lJq:bM
} bt2`elH|
8rXQK|A
vnrP;T=^
//获得文件长度 VEtdp*ot
public long getFileSize() j1sZRl)D
{ <)J83D0$E
int nFileLength = -1; ! ,*4d $
try{ %`F&,!d
URL url = new URL(siteInfoBean.getSSiteURL()); x U1](O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z}E.s@w
httpConnection.setRequestProperty("User-Agent","NetFox"); Z_tK3kQa@&
V7pe|]%r
At?]FjL6S
int responseCode=httpConnection.getResponseCode(); &E(KOfk#
if(responseCode>=400) oU`J~6.&S
{ ;YYo^9Lh}
processErrorCode(responseCode); HLa3lUo
return -2; //-2 represent access is error z(yJ/~m
} |d@%Vb_
qVpV ZH!
Q`Z=}^
String sHeader; qMj'%5/
YVpsf8R
v_7?Zik8E
for(int i=1;;i++) >&mNC\PA
{ RF,[1O-\O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 42{\u08Z
//Utility.log(in.readLine()); n&4 4Acs[
sHeader=httpConnection.getHeaderFieldKey(i); f7mN,_Lt
if(sHeader!=null) =[7[F)I~O
{ ^)|!nd
if(sHeader.equals("Content-Length")) ?$>#FKrt
{ ^>3q@,C]c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zOEdFU{x
break; &m8#^]*
} KTQy pv
} Xqz\%&G
else lhN2xg5x
break; O:'ENoQ:&
} wd 4]Z0;
} =.sg$VX
catch(IOException e){e.printStackTrace ();} 5vfzSJ
catch(Exception e){e.printStackTrace ();} !b=jD;<
O/|,rAE
O@Ro_sPG(
Utility.log(nFileLength); t,f)!D$
qt.G_fOz
08+cNT
return nFileLength; P Tc@MH)
} )37.H^7
MHm=X8eg
8BHtN
//保存下载信息（文件指针位置） Xq"_^
private void write_nPos() %ja8DRQ.
{ I|`/#BYbW
try{ U@6bH@v5
output = new DataOutputStream(new FileOutputStream(tmpFile)); iK(G t6w
output.writeInt(nStartPos.length); }^}fx [
for(int i=0;i<nStartPos.length;i++) |2YkZ nJn
{ kPt] [1jo
// output.writeLong(nPos); 5q.d$K |
output.writeLong(fileSplitterFetch.nStartPos); YV6@SXy
output.writeLong(fileSplitterFetch.nEndPos); {Xc^-A[~
} kvdiDo
output.close(); Qh0tU<jG
} fpDx)lQ
catch(IOException e){e.printStackTrace ();} }%&hxhR^t3
catch(Exception e){e.printStackTrace ();} &gNb+z+
} 9(\eL9^
tU5Z?QS
|<Cz#| ,q
//读取保存的下载信息（文件指针位置） &pL.hM^
private void read_nPos() #dvH0LX?
{ HP$GI
try{ D.Q9fa&P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {c7ZA%T~R
int nCount = input.readInt(); X\z`S##kj
nStartPos = new long[nCount]; ?)Psf/
nEndPos = new long[nCount]; (P+TOu-y\
for(int i=0;i<nStartPos.length;i++) !4"!PrZDB
{ n]15 ~GO.
nStartPos = input.readLong(); :c*_W /
nEndPos = input.readLong(); #|ppW fZQ
} ~x!"(
input.close(); '=M4(h
} YqJ `eLu
catch(IOException e){e.printStackTrace ();} 5i<E AKL
catch(Exception e){e.printStackTrace ();} )\k({S
} v$P<:M M
'e/= !"T
4 8}\
private void processErrorCode(int nErrorCode) }o'WR'LX
{ rz@FUU:&
System.err.println("Error Code : " + nErrorCode); )jS9p~FS
} {\SJr:
SY[7<BUZ
-$x5[6bN
//停止文件下载 k3 YDnMRA9
public void siteStop() T3JM8
{ M6j!_0j
bStop = true; vFz#A/1
for(int i=0;i<nStartPos.length;i++) h@^d Vg
fileSplitterFetch.splitterStop(); mmJ$+$JEk
Fm|h3.`V
RTLA*
} /qKO9M5A
} ~ ~"qT
//负责部分文件的抓取 wT taj08D
**FileSplitterFetch.java HW@r1[Y
*/ `veq/!
package NetFox; Im<i.a <`
iE}Lw&x
jQV.U~25Q
import java.io.*; ;PA^.RB
import java.net.*; odm!}stus
6>hW.aq}
cD6T4
public class FileSplitterFetch extends Thread { I?z*.yA*
2qN|<S&
}OJ,<!v2pc
String sURL; //File URL /Cl=;^)
long nStartPos; //File Snippet Start Position pE~>k:
long nEndPos; //File Snippet End Position Q!T+Jc9N
int nThreadID; //Thread's ID gQ0W>\xz
boolean bDownOver = false; //Downing is over ZDhl$m[m
boolean bStop = false; //Stop identical ,lUroO^^
FileAccessI fileAccessI = null; //File Access interface 0C,2gcq
*=KX0%3
8Q*477=I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (c'kZ9&
{ v!~;QO
this.sURL = sURL; &y~~Z [.F,
this.nStartPos = nStart; %"C%pA
this.nEndPos = nEnd; "fq8)
nThreadID = id; 4Gsbcl{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <jk.9$\$A
} ~R$Ko(N
#A@d;U%
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public void run() ,Qw\w,
{ SR<*yO
while(nStartPos < nEndPos && !bStop) Cbq|<p# #o
{ ]CnqPLqL
sZ7RiH+I
"AayU
try{ Bt?.8H6Y
URL url = new URL(sURL); Ev)aXP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B'U;i5u4'
httpConnection.setRequestProperty("User-Agent","NetFox"); Qt VZ)777
String sProperty = "bytes="+nStartPos+"-"; ss4<s 5:y
httpConnection.setRequestProperty("RANGE",sProperty); L>PPAI
Utility.log(sProperty); K]0K/~>8
~|!f6=
)`V__^
InputStream input = httpConnection.getInputStream(); G#(+p|n
//logResponseHead(httpConnection); Ozo)}
z!0}Kj
<M,A:u\qSQ
byte[] b = new byte[1024]; D,)^l@UP
int nRead; RO9oO7S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;=ci7IT'
{ >RL|W}tI4
nStartPos += fileAccessI.write(b,0,nRead); Hrdz1:#6,
//if(nThreadID == 1) /EXubU73
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KDW=x4*p
} .:(N1n'>1
50Kv4a"
ROfr
Utility.log("Thread " + nThreadID + " is over!"); ?->&)oAh
bDownOver = true; Dn9AOi!
//nPos = fileAccessI.write (b,0,nRead); _;x7vRWmN
} jh*aD=y
catch(Exception e){e.printStackTrace ();} U(t_uc5q
} r:n-?P
} b#2$Pd:(
6d%|yl
ti}g?\VT
//打印回应的头信息 ^^m3 11=
public void logResponseHead(HttpURLConnection con) #ivN-WKCl
{ TiF2c#Q*y
for(int i=1;;i++) zs_^m1t1s
{ {q}# Sq
String header=con.getHeaderFieldKey(i); F~Z~OqCS
if(header!=null) my|UlZ(qg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fsxZQ=-PW
Utility.log(header+" : "+con.getHeaderField(header)); !]v&/
else 1hT!~'
break; \;%DDw
} L9FijF7
} 4XprVB
>[U.P)7;
; {P"~(S%
public void splitterStop() 51\N+
{ Q.N, Q`P
bStop = true; tUp'cG
} -}W`
s=uWBh3J
q|[P[7z
} ;~>E^0M
t#p*{S 3u
mR? } gR
/* !/},k"p6
**FileAccess.java #78P_{#!
*//文件访问(定位，写) &Vtgh3I
package NetFox; y+C.2 ca
import java.io.*; %Ny`d49&
\*_@`1m
PUdJ>U
public class FileAccessI implements Serializable{ ^rDT+ x
3>`CZ]ip}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wM^_pah#Y5
RandomAccessFile oSavedFile; kUdl2["MZ
long nPos; !"dbK'jb^
{\?zqIM
Pw"o[8
public FileAccessI() throws IOException nVTCbV
{ ?`nF"u>
this("",0); B~_='0Gm[
} G$5N8k[2
*hT1_
Y{ho[%
public FileAccessI(String sName,long nPos) throws IOException -,;Iob56!
{ @[qGoai
oSavedFile = new RandomAccessFile(sName,"rw"); Dm=Em-ST6
this.nPos = nPos; vFK&63
oSavedFile.seek(nPos); 6;lJs,I1w{
} y1JxAj
ERW>G{+
)TceNH
public synchronized int write(byte[] b,int nStart,int nLen) G36}4
{ m\h/D7zg
int n = -1; s_=/p5\
try{ )U`"3R
oSavedFile.write(b,nStart,nLen); D<rO:Er?*a
n = nLen; &=sVq^d@qe
} H?M#7K~[
catch(IOException e) S^@I4Z
{ N#;k;Z'iL
e.printStackTrace (); kF9T 9
} rAdYBr=0
74c1i
JTw'ecFev
return n; .(Gq9m[~8H
} 7-M$c7S
Jlw oSe:S
{d\erG(
} )$/Gh&1G
t6;Ln().Hw
G .~Psw#
/* }b+tD3+
**SiteInfoBean.java TqNEU<S/t
*/ D<[4}og&]
package NetFox; D?rQQxb
X[8m76/V
]@op
public class SiteInfoBean { ;T}#-`O_Im
K1Tq7/N
NIDK:qdR
private String sSiteURL; //Site's URL Z8$@}|jN
private String sFilePath; //Saved File's Path Xc2Oa
private String sFileName; //Saved File's Name tw8@&8"
private int nSplitter; //Count of Splited Downloading File >JFAE5tj&2
}XCHoB
@3bQ2jn
public SiteInfoBean() dOq*W<%
{//nSplitter的缺省值为5 `j088<?j
//default value of nSplitter is 5 *1V}vJvi
this("","","",5); `LL#Aia
} 8#S|jBV
od|w)?16
lhAwTOn`Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4J2NIFZ
{ CD(2A,u)/
sSiteURL= sURL; $=n|MbFl
sFilePath = sPath; ]yN]^%PYH
sFileName = sName; ;$(a+?
this.nSplitter = nSpiltter; mFOuE5
GVZ/`^ndM
&|xN=U/
} `9eE139V='
|sHIT<=m
;}3wT,=sN
public String getSSiteURL() RX:\@c&
{ "8VCXD
return sSiteURL; =LuH:VM&
} GAbX.9[V
g ZhE\
3*64)Ol7t]
public void setSSiteURL(String value) 2(LS<HqP[
{ qev1bBW
sSiteURL = value; L~Epd.,Dt
} ,JRYG<O_T
gm9e-QIHK
qX`?4"4
public String getSFilePath() ~!j1</$_
{ I-4csw<Qy
return sFilePath; -DhF> 4f
} +60zJ4
e2;19bj&
$zbm!._~DA
public void setSFilePath(String value) +wwpaR`
{ ZT95g
sFilePath = value; jE2k\\<a
} ry3;60E\)
j% !
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public String getSFileName() J6_Hlt
{ `,Q uO
return sFileName; C78YHjy
} 2X;,s`)
~UB@IV6O
i0Qg[%{9#
public void setSFileName(String value) lyfLkBF
{ x "]%q^x
sFileName = value; qbu Lcy3
} Z%6I$KAN8
'CjcOI s
h&L+Qx
public int getNSplitter() z<ptrH
{ G9:[W"P
return nSplitter; ,*?bET $
} 9yajtR
;n00kel$
j!iimdq
public void setNSplitter(int nCount) M/:kh,3
{ c_x6FoE;L
nSplitter = nCount; '{QbjG%<P
} *5hg}[n2
} bqFGDmu6'
Jj*XnL*
bT,]=h"0
/* L9Z:>i?
**Utility.java -wvrc3F
*/ 0SwWLq
package NetFox; 0qnToV;
!F/;WjHz
Dh BUMDoB
public class Utility { =S4_^UY;
`XB(d@%
b4Zkj2L
public Utility() F +D2 xN@
{ ;3h[=hyS
_' Xt
DhG2!'N
} uwsGtgd&
I5wf|wB-
//线程睡眠 .wtb7U;7
public static void sleep(int nSecond) V?kJYf(<
{ iS&fp[Th
try{ Xnt`7L<L
Thread.sleep(nSecond); rOm)s'
} fa8vY
catch(Exception e) .!\y<9
{ gs_"H
e.printStackTrace (); &"BmCDOq
} HB\<nK
} 4C/
|fYNkD8z1
//日志 { .B^
public static void log(String sMsg) sycN
{ /FJAI
System.err.println(sMsg); kpsus \T
} )a.w4dH
w")VcAq
hzg&OW=:
public static void log(int sMsg) rV<yM$IA
{ /(8Usu?g.
System.err.println(sMsg); =SA@3)kHH
} :O-Y67>&
} WEFYV=I\
H^_[nL
M\ vj&T{k
/* {wih)XNY
**TestMethod.java TFb9gOTJ
*/ {-2I^Ym 5i
package NetFox; M&Sjo' ( .
]hpocr
#WwQ^6ESc
public class TestMethod { m]R< :_
?k<i e2
8`Q8Mct$<
public TestMethod() B4bC6$Lg
{ ///xx/weblogic60b2_win.exe JOS,>;;F4
try{ " |[w.`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _Isju S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lO3$V JI
SiteFileFetch fileFetch = new SiteFileFetch(bean); lZ.x@hDS
fileFetch.start(); 75v 5/5zRn
} d@#!,P5`
catch(Exception e){e.printStackTrace ();} r"d/9
qX^#fk7]
lCLz!k2di
} =o^oMn
58\Rl
vQ>x5\r5O_
public static void main(String[] args) -lV]((I&
{ 6+u}'mSj8
new TestMethod(); /kqW
} Tjma'3H*T0
} CMB:%
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