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)); VgIk'.
} 97\K]Tr
for(int i=0;i<nEndPos.length-1;i++) {*F =&D
{ hZ452W
nEndPos = nStartPos[i+1]; )1B?<4
} }q]*aADe
nEndPos[nEndPos.length-1] = nFileLength; 8..|-<w
} j3;W-c`5
} @O'NJh{D`
<!FcQVH+L
P?f${t+
//启动子线程 /7\q#qIm:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]?H12xz
for(int i=0;i<nStartPos.length;i++) YcX"Z~O6j=
{ Jh=.}FXnjL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Cj1VjAg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J-'XT_k:iM
nStartPos,nEndPos,i); LYL_Ah'=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BXU0f%"8U
fileSplitterFetch.start(); gAorb\iJ
} G!sfp}qW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4]m{^z`1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n/(}|xYU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e,p*R?Y{[
nEndPos = " + nFileLength); 5o 5DG
// fileSplitterFetch[nPos.length-1].start(); ;z9,c
aV|VC$
B-]bhA4|:
//等待子线程结束 =,;$d&#*h
//int count = 0; "1^tVw|
//是否结束while循环 _[z)%`kay
boolean breakWhile = false; X9|*`h<
|3E|VGm~
Zl&ED{k<
while(!bStop) x3FB`3y~s
{ %G2g @2
write_nPos(); bj@R[!ss
Utility.sleep(500); <";1[A%7<
breakWhile = true; ^j${#Q
_F[a2PE2+
_;5zA"~c#@
for(int i=0;i<nStartPos.length;i++) i0wBZ i?
{ @]#[TbNo
if(!fileSplitterFetch.bDownOver) h%u!UHA
{ &l]F&-
breakWhile = false; 9-{+U,3)
break; dl8f]y#Q
} ;`pIq-=
} k6z ]-XG
if(breakWhile) +,YK}?e
break; -f ~1Id
am3.Dt2\
k3t]lGp
//count++; C.#Ha-@uz
//if(count>4) R'tvF$3=i
// siteStop(); ZG1TRF "
} PPV T2;9
P3W3+pwq
6(7{|iY
System.err.println("文件下载结束！"); &L?]w=*
} W0mvwYON[
catch(Exception e){e.printStackTrace ();} $Bc3| `K1v
} `u_MdB}<x;
.YvIVQ
U_'M9g{,<
//获得文件长度 X,G"#j^
public long getFileSize() ,.2qh|Ol
{ X=f%!
int nFileLength = -1; ._j?1Fw`
try{ 0Cf'\2
URL url = new URL(siteInfoBean.getSSiteURL()); Q.jThP`p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $Lbamg->E
httpConnection.setRequestProperty("User-Agent","NetFox"); C:sgT6
?MSwr_eZH
NpM;vO
int responseCode=httpConnection.getResponseCode(); `_1fa7,z
if(responseCode>=400) >h~ik/|*
{ /CyFe<t
processErrorCode(responseCode); p`\>GWuT!
return -2; //-2 represent access is error R#y"SxD()
} 9^H.[t
ADOA&r[
jHE^d<=O^
String sHeader; tKuJ &I~
l+&DBw[
iT|7**+3
for(int i=1;;i++) j-"34
{ vN_ 8qzWk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V'dw=W17V
//Utility.log(in.readLine()); m}D;=>2$
sHeader=httpConnection.getHeaderFieldKey(i); NhTJB7
if(sHeader!=null) -e0[$v
{ 6!itr"
if(sHeader.equals("Content-Length")) FAc^[~E
{ ojm IEzsz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a @3s71
break; 0:I<TJ~P
} IaOR%Bg
} stW G`>X
else K8[Um!(
break; #UwX~
} [742s]j
} >)diXe}j
catch(IOException e){e.printStackTrace ();} A1Uy|Dl
catch(Exception e){e.printStackTrace ();} 2)0J@r'
l. cp[
:HrFbq
Utility.log(nFileLength); ?>V>6cDQ
!kb:g]X
I][&*V1
return nFileLength; Np$&8v+en
} 1\aTA,
zv;xxAX
Y}2Sr-@u
//保存下载信息（文件指针位置） [kxOv7a
private void write_nPos() ^LB]
{ Z'!ORn#M
try{ :IJ<Mmb
output = new DataOutputStream(new FileOutputStream(tmpFile)); O8" t.W
output.writeInt(nStartPos.length); t18j2P>`
for(int i=0;i<nStartPos.length;i++) ;&}z L.!jo
{ ),Yk53G6c
// output.writeLong(nPos); uHmvHA~/c8
output.writeLong(fileSplitterFetch.nStartPos); W|zPV`
output.writeLong(fileSplitterFetch.nEndPos); E11C@%
} Dic|n@_Fy
output.close(); MXEI/mDYK
} EN/t5d
catch(IOException e){e.printStackTrace ();} =6=:OId
catch(Exception e){e.printStackTrace ();} ?Y8hy|`
} BB69U
BgdUG:;&
^=5y;
//读取保存的下载信息（文件指针位置） =23@"ji@D
private void read_nPos() 4J(-~
{ =0PGE#d{t
try{ 7 wEv`5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VMJaL}J]
int nCount = input.readInt(); TKAs@X,t
nStartPos = new long[nCount]; I''n1v?N
nEndPos = new long[nCount]; m]fUV8U
for(int i=0;i<nStartPos.length;i++) aL90:,V
{ {~Jk(c~I
nStartPos = input.readLong(); h2Th)&Fb>
nEndPos = input.readLong(); X?< L<:.
} (&v|,.c^)1
input.close(); 4L{]!dox
} kMnG1K
catch(IOException e){e.printStackTrace ();} ^_P?EJ,)`
catch(Exception e){e.printStackTrace ();} cRbA+0m>
} &Q}%b7
2@z.ory.
~a`xI
private void processErrorCode(int nErrorCode) u'_}4qhCC;
{ [v*q%Mi_
System.err.println("Error Code : " + nErrorCode); ##xvuLy-6
} 6g"h}p\{S
\**j\m
UXpp1/d|e
//停止文件下载 uSQ#Y^V_
public void siteStop() wik<#ke
{ +YW;63"o
bStop = true; BQg3+w:>
for(int i=0;i<nStartPos.length;i++) `G`R|B
fileSplitterFetch.splitterStop(); mR XRuK
&V<f;PF(I
Mz2TwU_
} L)F4)VL
} {GnZ@Q:F
//负责部分文件的抓取 g\.$4N
**FileSplitterFetch.java (g X8iKl
*/ URbB2 Bi
package NetFox; |D/a}Av>B
ysIhUpd
G&1bhi52
import java.io.*; +>!nqp
import java.net.*; Fc\]*
*kqC^2t
OM\1TD/-
public class FileSplitterFetch extends Thread { =IQ}Y_xr
zN]%p>,)HB
V8B4e4F
String sURL; //File URL a <?~1pWtc
long nStartPos; //File Snippet Start Position vVa|E# [
long nEndPos; //File Snippet End Position W~D_+[P|_
int nThreadID; //Thread's ID sr&W+4T
boolean bDownOver = false; //Downing is over 0D@$
boolean bStop = false; //Stop identical AzXLlQ
FileAccessI fileAccessI = null; //File Access interface wDW%v@
[*zg? ur
>Q=^X3to
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [NO4Wzc
{ 23L>)Q
this.sURL = sURL; ^ `Ozw^~
this.nStartPos = nStart; !^su=c
this.nEndPos = nEnd; 7(.Z8AO
nThreadID = id; H#;*kc a4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x@rQ7K>
} b=:ud[h
wv{ Qx^
o|z@h][(l(
public void run() 4l%W]'
{ \b(&-=(
while(nStartPos < nEndPos && !bStop) Wmcd{MOS
{ '0q$qN
QE[<Y3M
mWaij]1>
try{ Y 2ANt w@
URL url = new URL(sURL); XxmWj-=qO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OR~ui[w
httpConnection.setRequestProperty("User-Agent","NetFox"); IV. })8
String sProperty = "bytes="+nStartPos+"-"; {E Ay~lo
httpConnection.setRequestProperty("RANGE",sProperty); 7mMGH(
Utility.log(sProperty); S5TVfV5LI
MYy58N
NC-K`)
InputStream input = httpConnection.getInputStream(); >;c);|'}q
//logResponseHead(httpConnection); Y#68_%[
%CiF;wJ
%w65)BFQ
byte[] b = new byte[1024]; k"i3$^v8
int nRead; ANu>*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iVZ}+Ct<"
{ .@OQ$D<
nStartPos += fileAccessI.write(b,0,nRead); *%KIq/V
//if(nThreadID == 1) {ac$4#Bp[B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :\"0jQ.y|
} BkXv4|UE
{HEWU<5
8~C}0H
Utility.log("Thread " + nThreadID + " is over!"); l6HtZ(
bDownOver = true; ?{f6su@rW
//nPos = fileAccessI.write (b,0,nRead); `X@\Zv=}
} jC>ZMy8U)4
catch(Exception e){e.printStackTrace ();} N { oVz],
} St%x\[D
} [6mK<A,/
q\o#<'F1J
-@w,tbc$
//打印回应的头信息 ~+4lmslR
public void logResponseHead(HttpURLConnection con) 06.%9R{
{ f~mwDkf?L
for(int i=1;;i++) qK%N{ro[{?
{ u9S*2'
String header=con.getHeaderFieldKey(i); "H(3pl.
if(header!=null) ]w6F%d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pwfQqPC#_
Utility.log(header+" : "+con.getHeaderField(header)); x&;AY
else Z.gb'
break; &EV%g6
} c2g[w;0"
} cwzkA,e@
D|ze0A@
u/j\pDl.
public void splitterStop() -"nkC
{ .Bl:hk\
bStop = true; 1w7tRw
} (}X5*BB&
I*a@_EO
,byc!P
} /Kli C\
R5=J:o
-rcEG!
/* =_k
**FileAccess.java [ft6xI
*//文件访问(定位，写) 3\m!
package NetFox; Ql5bjlQdO
import java.io.*; 9)tb=
Xf&YcHo
p)B/(%
public class FileAccessI implements Serializable{ QO;Dyef7b
O"~[njwkE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s&nat4{B
RandomAccessFile oSavedFile; m^L!_~
long nPos; bQ3<>e\%B
kfas4mkc
Q9OCf"n$
public FileAccessI() throws IOException h!SsIy(
{ &l2xh~L
this("",0); [G8EX3
} A-4;$ QSm
lGYW[0dy
:|V650/
public FileAccessI(String sName,long nPos) throws IOException yrEh5v:
{ X9?)P5h=
oSavedFile = new RandomAccessFile(sName,"rw"); ] hK}ASC
this.nPos = nPos; 5;KJ0N*-
oSavedFile.seek(nPos); _s@PL59,
} $#f_p-N
^*fD
.:&`PaMt
public synchronized int write(byte[] b,int nStart,int nLen) nyPeN?-
{ A^).i_&#
int n = -1; c6i7f:'-0
try{ MkMDI)Y|
oSavedFile.write(b,nStart,nLen); | U0s1f
n = nLen; -B-G$ii
} t!3s@
catch(IOException e) lv/im/]v
{ X>`03?L
e.printStackTrace (); qZF&^pCF}
} mmJnE
1A'eH:$
;8PO}{rD
return n; zB0*KgAn{
} bDl#806PL
9NwUXh(:(
F<{,W-my `
} |HT7m5tu4
BNJ0D
cdkEK
/* + Fo^NT
**SiteInfoBean.java t[+bZUS$~
*/ pnSKIn
package NetFox; kiJ=C2'&
Lqxhy s
rM.Pc?Z
public class SiteInfoBean { uz+WVmb
kCD]&
PP$2s]{
private String sSiteURL; //Site's URL \h3HaNC
private String sFilePath; //Saved File's Path P\K#q%8
private String sFileName; //Saved File's Name Pa0W|q#?X
private int nSplitter; //Count of Splited Downloading File !0hyp |F:>
>6yQuB
py7Zh%k
public SiteInfoBean() ppn 8
{//nSplitter的缺省值为5 tnUfi8\ob
//default value of nSplitter is 5 Vx.c`/
this("","","",5); ,gNZHKNq
} \:Tq0|]Px
^_3Ey
` Ny(S2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b#N P*L&
{ AJ>E\DK0]
sSiteURL= sURL; \( V1-,
sFilePath = sPath; +`wr{kB$~
sFileName = sName; m%u`#67oK
this.nSplitter = nSpiltter; >b"@{MZ@t
Xj+_"0 #
\^,Jh|T
} |MKR&%Na
QyL]-zNg
d+)LK~
public String getSSiteURL() $!. [R}
{ 3<<wHK;)
return sSiteURL; IY6Ll6OK
} !VIxEu^ke
Zs/-/C|
Dti-*LB1
public void setSSiteURL(String value) %8I^&~E1
{ 0vLx={i
sSiteURL = value; -w2^26ax
} XGR63hXND
M:OZWYQ
{@L{l1|0
public String getSFilePath() T_2'=7
{ mY"Dw^)
return sFilePath; yx`@f8Kr
} i#YDdz
gNxv.6Pp=
Q(N'Oj:J
public void setSFilePath(String value) (9( xJ)
{ "UD)3_R
sFilePath = value; 5YPIv-
} %LC)sSq{H
q*R~gEi#yk
FEhBhv|m
public String getSFileName() w7~]c,$y.
{ b?0WA.[{
return sFileName; BeRs;^r+
} NM9ViYm>P
qDswFs(
"fNv(> -7s
public void setSFileName(String value) YRZw|H{>t
{ 6flO;d/v
sFileName = value; h\#4[/
} 5[zr(FuE
`4@`G:6BL
S|u5RU8*"|
public int getNSplitter() </<z7V,{
{ q{*[uJ}Xc"
return nSplitter; fU.hb%m)Q\
} "o;%em*Bc
sdXchVC
P >0S ZP
public void setNSplitter(int nCount) yT3K 2A
{ Qh3+4nLFtb
nSplitter = nCount; ;/m>c{
} ~:!&}e5
} UBM8l
L}8 }Pns?&
&C,]c#-+
/* /s)It
**Utility.java Ca"i<[8
*/ 3s:)CXO
package NetFox; hhjsg?4uL
]]V=\.y
,V4pFQzL
public class Utility { &U.y):
Z+J~moW `
,aWfGh#$
public Utility() _["97>q
{ g5Hsz,x
&xlOsr/n
0Z%<H\Z
} OK}8BY
; zy;M5l5.
//线程睡眠 A]V<K[9:b
public static void sleep(int nSecond) dnPr2oI?I
{ ^eYJ7&t
try{ WWTJ%Rd|
Thread.sleep(nSecond); Z[j-.,Qu
} 8{Svax(
catch(Exception e) ~>$(5s2
{ N)z] F9Kg
e.printStackTrace (); [7)#3
} |4Q><6"G
} Z3T26Uk
{24Pv#ZG#^
//日志 ^h|'\-d\
public static void log(String sMsg) s3T6"%S`
{ :\1&5Pm]
System.err.println(sMsg); :(x 90;DW
} X_|} b[b
U(qM( E
})w5`?Y
public static void log(int sMsg) Y!s/uvRI
{ qdu:kA:]
System.err.println(sMsg); 9zd)[4%=
} ln!KL'T]
} *XzUqK
I`KN8ll
Z#W`0G>'
/* .g&BA15<F6
**TestMethod.java 7y`~T+
*/ `0 F"zu
package NetFox; o_$r*Z|HG
!p9F'7;Y<
uTJ?@^nq
public class TestMethod { QU4'x4YS
Yc5$915
KoXXNJax
public TestMethod() MDCf(LhEH
{ ///xx/weblogic60b2_win.exe bFx?HM.AGW
try{ W]*wxzf!5z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3i$AR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2Uk8{d
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,[hJi3xM
fileFetch.start(); >) :d38M
} XKK*RVs#
catch(Exception e){e.printStackTrace ();} },L[bDOV07
]V]o%onW
?^+|V,<
} +1623E
xO@OkCue
jH G(d$h
public static void main(String[] args) ^~I
{ 4%{m7CK}
new TestMethod(); *ZEs5`x
} MdfkC6P
} 8ksDXf`.
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