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)); g74z]Uj.B
} |-Esc|J(
for(int i=0;i<nEndPos.length-1;i++) yO,`"Dc_0
{ zpr@!76
nEndPos = nStartPos[i+1]; "~2#!bK7
} UK_aqB
nEndPos[nEndPos.length-1] = nFileLength; KW7?: x
} j484b2uj1
} U;Ll.BFP
J1Ki2I=
u}LX,B-n(
//启动子线程 /<7C[^h{-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !+DJhw&c,
for(int i=0;i<nStartPos.length;i++) ]\ 2RVDC
{ oYh<k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .i&ZT}v3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), PSf5p\<5
nStartPos,nEndPos,i); LQ(5D_yG.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {29S`-|P
fileSplitterFetch.start(); jy(+ 0F
} Q6!v3P/h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +5t bK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1^f.5@tV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mhi90Jc
nEndPos = " + nFileLength); #;"D)C
// fileSplitterFetch[nPos.length-1].start(); iA3>X-x
2Jo~m_
}\u%)uZ
//等待子线程结束 M9s43XL(&
//int count = 0; 4OOn,09
//是否结束while循环 puS&S *
boolean breakWhile = false; ]Q4PbW
a\{1UD
S'!q}|7X3
while(!bStop) sP?$G8-^
{ N=T.l*8
write_nPos(); /j' B\,
Utility.sleep(500); {;&B^uz ]
breakWhile = true; 6 tc:A5mK
gmRT1T
iO*`(s
for(int i=0;i<nStartPos.length;i++) (/SGT$#8
{ e`Co,>W/
if(!fileSplitterFetch.bDownOver) -*|:v67C&
{ kYxl1nv
breakWhile = false; a(@p0YpKT
break; ;NH~9# t:
} o#xgrMB
} !8Z2X!$m{<
if(breakWhile) Re*|$r#
break; l]_b;iux
BrJ o!@<
mG831v?
//count++; Y5ogi)
//if(count>4) 2yln7[a
// siteStop(); =n-z;/NL
} ?wd|G4.Vo
2yN%~C?$
T&r +G!2
System.err.println("文件下载结束！"); #>8T*B
} JbE?a[Eg?
catch(Exception e){e.printStackTrace ();} l80bHp=
} lDW!Fg
$]@O/[
YywEZ?X
//获得文件长度 J&M1t#UN
public long getFileSize() [@m[V1D
{ 24|
int nFileLength = -1; )YuRjBcp,"
try{ '_B_&is
URL url = new URL(siteInfoBean.getSSiteURL()); >']+OrQH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ko#4z%Yq
httpConnection.setRequestProperty("User-Agent","NetFox"); </.z1 $
||uZ bP@
cV-i*L4X
int responseCode=httpConnection.getResponseCode(); OI+E (nA
if(responseCode>=400) ibvJWg
{ UL+E,=
processErrorCode(responseCode); q"S(7xWS
return -2; //-2 represent access is error 8QV t, 'I
} Vo%Yf9C
OCCEL9d
;4,'y
String sHeader; \M9h&I\7
A8J8u,u9
hp*<x4%*a"
for(int i=1;;i++) ?cJY B)
{ jZRhKT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RU6KIg{H
//Utility.log(in.readLine()); ?0{yq>fTu
sHeader=httpConnection.getHeaderFieldKey(i); c15r':.5
if(sHeader!=null) c<?[d!vI
{ I~)cYl:|G
if(sHeader.equals("Content-Length")) cf)J )
{ m4@MxQm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I:i<>kG
break; P.cO6+jGR
} ZRnL_z~
} [(|^O>k8c
else UFe(4]^
break; s"i~6})K<$
} CZY7S*fL
} <c+K3P'3?
catch(IOException e){e.printStackTrace ();} bg}+\/78#
catch(Exception e){e.printStackTrace ();} 4O(@'#LLz
j$vK<SF
"b]#MO}P
Utility.log(nFileLength); e0 u,zg+m
k9mi5Oc
`4V"s-T'
return nFileLength; DI,K(_@G
} .%'Z~|K4
F~6#LT
MS*G-C
//保存下载信息（文件指针位置） \3zp)J
private void write_nPos() .'1SZe7O
{ , ECLqs%
try{ L\e>B>u
output = new DataOutputStream(new FileOutputStream(tmpFile)); &Jy)U
output.writeInt(nStartPos.length); rCBfD
for(int i=0;i<nStartPos.length;i++) 'e@=^FC
{ x6;j<m5Mjx
// output.writeLong(nPos); Dx-KMiQ,"(
output.writeLong(fileSplitterFetch.nStartPos); +@<KC
output.writeLong(fileSplitterFetch.nEndPos); 4Po)xo
} inAAgW#s}
output.close(); [h&BAR/ 2
} +th%enRB
catch(IOException e){e.printStackTrace ();} _w(ln9
catch(Exception e){e.printStackTrace ();} }$kQs!#
} `uo,__y
!MVj=(
y3eHF^K+$
//读取保存的下载信息（文件指针位置） % /}WUP^H
private void read_nPos() v,OpTu:1
{ 3s*(uS(
try{ 'O?~p55T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6CCbBA
int nCount = input.readInt(); Pc_VY>Ty
nStartPos = new long[nCount]; /nZ;v4
nEndPos = new long[nCount]; F$MX,,4U
for(int i=0;i<nStartPos.length;i++) u~1o(Zn =
{ T$+-IAE
nStartPos = input.readLong(); r$(~j^<s
nEndPos = input.readLong(); . +
} yT8=l"-[G
input.close(); 6#e::GD
} EU-]sTJLF
catch(IOException e){e.printStackTrace ();} r0]4=6U
catch(Exception e){e.printStackTrace ();} 57,dw-|xi
} IMGP'g
XfYC7-e9c
Wu1{[a|
private void processErrorCode(int nErrorCode) x@>&IBiL
{ fJAnKUF)
System.err.println("Error Code : " + nErrorCode); *|#T8t,}n
} M*eJ JY
TX [%(ft
\e3`/D
//停止文件下载 sTRJ:fR
public void siteStop() tBATZ0nK`Q
{ ,u9M<B<F
bStop = true; |JF@6
for(int i=0;i<nStartPos.length;i++) .;7> y7$*
fileSplitterFetch.splitterStop(); % ps$qB'
t2HJsMX
;)AfB#:d
} KhbYr$
} GB7/x*u
//负责部分文件的抓取 aGZi9O7G}
**FileSplitterFetch.java {LHR!~d}5f
*/ 2d>hi32I
package NetFox; v"& pQ
K14^JAdY/
yifY%!@Xu
import java.io.*; uw(NG.4
import java.net.*; q$(5Vd:
Cqii}
l:#-d.z#
public class FileSplitterFetch extends Thread { {--0z3n>
z!;1i[|x
yXI >I
String sURL; //File URL j]|U
long nStartPos; //File Snippet Start Position _A13[Mt3
long nEndPos; //File Snippet End Position DGW+>\G
int nThreadID; //Thread's ID /S5|wNu
boolean bDownOver = false; //Downing is over P 3MhU;
boolean bStop = false; //Stop identical "tjLc6Xl^
FileAccessI fileAccessI = null; //File Access interface ,)PiP/3B
;Gx)Noo/>
-=s(l.?Hm5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bXUy9-L
{ No]~jnqDM
this.sURL = sURL; 7dsefNPb
this.nStartPos = nStart; H~ZV*[A`
this.nEndPos = nEnd; rc&%m
nThreadID = id; <)+y=m\eJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !EUan
} gs!(;N\j|
Ookh<ES>
9zYVC[o
public void run() uqz]J$
{ 241*!
while(nStartPos < nEndPos && !bStop) |5Xq0nvCe
{ .bBdQpF-
W9NX=gE4
Xpzfm7CB/
try{ %v20~xW:o
URL url = new URL(sURL); N F)~W#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z5ij(RE]
httpConnection.setRequestProperty("User-Agent","NetFox"); k)EX(T\
String sProperty = "bytes="+nStartPos+"-"; boDt`2=
httpConnection.setRequestProperty("RANGE",sProperty); J:V?EE,\-
Utility.log(sProperty); B)d(TP,>
lNSLs"x^
~69&6C1Ch
InputStream input = httpConnection.getInputStream(); P.gb1$7<
//logResponseHead(httpConnection); .Wjs~0c
5\z`-)
wI(M^8F_Mf
byte[] b = new byte[1024]; iLSr*` o
int nRead; W6Y]N/v3>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AK@9?_D
{ dAuJXGo
nStartPos += fileAccessI.write(b,0,nRead); om1eQp0N
//if(nThreadID == 1) ;^Dpl'v%\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KCs[/]
} h$2</J"
% >=!p
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Utility.log("Thread " + nThreadID + " is over!"); $< JaLS
bDownOver = true; ov, hI>0!D
//nPos = fileAccessI.write (b,0,nRead); _bNzXF
} .[_L=_.
catch(Exception e){e.printStackTrace ();} 5 sX+~Q
} 7'Mm205\
} DMOMh#[
\.-bZ$
w(L4A0K[
//打印回应的头信息 qi^7
public void logResponseHead(HttpURLConnection con) 9iQq.$A.
{ |!4K!_y
for(int i=1;;i++) A*\.NTM
{ F1yqxWHeo
String header=con.getHeaderFieldKey(i); " )1V]}+m
if(header!=null) ~nay"g:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GB=X5<;
Utility.log(header+" : "+con.getHeaderField(header)); $|@ (
else n"c[,k+R`U
break; glDu2a,Q
} %WjXg:R
} MDnua
<<][hQs
[<@.eH$hU/
public void splitterStop() &OH={Au
{ I=`U7Bis"
bStop = true; ,?^ p(w
} ?Lk)gO^C
V2wb%;q
s Z].8.
} yb\_zE\
k%WTJbuG<)
UM"- nZ>[
/* +nFu|qM}
**FileAccess.java 1~NT.tY
*//文件访问(定位，写) hcsP2 0s
package NetFox; t.i 8 2Q
import java.io.*; _@ qjV~%Sy
,l\-xSM
4V)kx[j
public class FileAccessI implements Serializable{ KJ)k =mJ
rZ}:Z'`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kTOzSiq
RandomAccessFile oSavedFile; y51e%n$
long nPos; DEKP5?]
$9_xGfx}
Y!w`YYKP
public FileAccessI() throws IOException *&^Pj%DX
{ yg<R=$n,Q
this("",0); 0d)M\lG
} wDal5GJp
2*;~S44
9<6;Hr,>G
public FileAccessI(String sName,long nPos) throws IOException _Xe>V0
{ Q4#m\KK;i9
oSavedFile = new RandomAccessFile(sName,"rw"); /K@XzwM
this.nPos = nPos; {4<C_52t
oSavedFile.seek(nPos); c<B/V0]
} & p
dd%6t
JzQ_{J`k
public synchronized int write(byte[] b,int nStart,int nLen) )4e.k$X^
{ n,y ZRY
int n = -1; ]vUwG--*
try{ G:<aB
oSavedFile.write(b,nStart,nLen); 'x#~'v*
n = nLen; {I%cxQ#y
} J5K^^RUR
catch(IOException e) Uiw2oi&_
{ nfbR P t
e.printStackTrace (); #jvtUS\
} b|:YIXml
I3L<[-ZE
8b&/k8i:
return n; w,.TTTad
} n:?a$Ldgm
2*& ^v
?(1y
} |mfvr*7
3qC}0CP*
-=Q*Ml#I
/* >1Ibc=}g
**SiteInfoBean.java s2V:cMXFn
*/ L~OvY
package NetFox; h7Kzq{$
%YscBG
97*p+T<yp
public class SiteInfoBean { A|4[vz9>H
""G'rN_=Bi
oJz^|dW
private String sSiteURL; //Site's URL x|Bf-kc[#Q
private String sFilePath; //Saved File's Path !wVM= z^G
private String sFileName; //Saved File's Name j</: WRA`]
private int nSplitter; //Count of Splited Downloading File *i%.;Z"
kbQ>a5`,x
)7Wf@@R'F
public SiteInfoBean() 6A-|[(NS
{//nSplitter的缺省值为5 F^;ez/Gl
//default value of nSplitter is 5 X.{S*E:$u
this("","","",5); N~)_DjQP5
} |/{=ww8|
",; H`V
Wd:uV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l'_r:b
{ zRr*7G
sSiteURL= sURL; aX'*pK/-
sFilePath = sPath; %P|/A+Mg"
sFileName = sName; ?0SJfh
this.nSplitter = nSpiltter; d\8l`Krs[_
x'<X!gw
)3EY;
} igPX#$0XU
oZ|\vA%4^
`d}2O%P
public String getSSiteURL() 2FJ*f/
{ 3f{3NzN
return sSiteURL; &V/MmmT
} k5pN
2\{zmc}G-0
%Q|Atgp
public void setSSiteURL(String value) HG^'I+Yn
{ `b$.%S8uj=
sSiteURL = value; o>pJPV
} XwaXdvmK
fNFY$:4X
C~/a-
public String getSFilePath() Sdryol<
{ Qvhl4-XjZa
return sFilePath; cbTm'}R(G
} /j.9$H'y
+6+i!Sip
C,4e"yynb
public void setSFilePath(String value) 61U09s%\0
{ F:S}w
sFilePath = value; 5nx1i
} ,z=LY5_z)
tKXIk9e
'm$L Ij?@
public String getSFileName() p4Z(^+Aa
{ Ig{0Z">
return sFileName; CU!Dhm/U
} 2D5StCF$O
3ckclO\|>
FGzwhgy
public void setSFileName(String value) ;!Fn1|)
{ G' 1'/
sFileName = value; V!~wj
} TWX.D`W
I7]8Y=xf
f _:A0
public int getNSplitter() CAf6:^0
{ P.DK0VgY
return nSplitter; gjlx~.0d
} xoME9u0x4
UPGtj"2v-
h{qgEIk&
public void setNSplitter(int nCount) 2~[juWbz
{ kq-) ^,{y
nSplitter = nCount; [V`r^
} &7s.`
} %a7$QF]
~}Pfu
NxILRKwO
/* ^ZCD ~P_=
**Utility.java ~VB1OLgv#.
*/ 5:?!=<=
package NetFox; \{D" !e
iURe([@
5lum$5
public class Utility { y B$x>Q'C(
|vC~HJpuv'
2KZneS`
public Utility() %l%HHT
{ [N'h%1]\
VtohL+
D m9sL!
} \)Cl%Em
phz&zlD
//线程睡眠 |l!aB(NW
public static void sleep(int nSecond) P2nu;I_&
{ `0R./|bv\I
try{ d"Y{UE
Thread.sleep(nSecond); d d;T-wa}
} ##ANrG l
catch(Exception e) =BrRYA
{ >R=|Wo`Ri
e.printStackTrace (); fXB0j;A
} tf G@&&%9
} 13wE"-
XX~,>Q}H=
//日志 wyG;8I
public static void log(String sMsg) R}ecc
{ .wr>]yN
System.err.println(sMsg); dqAw5[qMJ
} BerwI 7!=
2?i7UvV
eQ}4;^;M-
public static void log(int sMsg) 92-I~ !d
{ A)KZa"EX
System.err.println(sMsg); ]%(2hY~i
} oXS}IL og'
} ?1".;foZ
.sA.C]f
hzC>~Ub5
/* {:W$LWET
**TestMethod.java -.3w^D"l
*/ L8n|m!MOD
package NetFox; Ct|A:/z(
`,0}ZzaV&
@lt#Nz
public class TestMethod { bN88ua}k{
O1kl70,`R
9C i-v/M]
public TestMethod() DeYV$W B
{ ///xx/weblogic60b2_win.exe D3A/l
try{ u-C)v*#L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iyog`s c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -{+}@?
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ca3~/KrM
fileFetch.start(); ]:\dPw`A
} KYN0
catch(Exception e){e.printStackTrace ();} D sWSGb
lNBL4yM
6`-jPR
} [fIg{Q
yCX?!E;La
4Z,!zFS$`
public static void main(String[] args) f V(J|
{ cs'{5!i]
new TestMethod(); OUXR
} +t;7tQDVB
} "wHFN>5B
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