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)); OYGh!sW
} (yFR;5Fo
for(int i=0;i<nEndPos.length-1;i++) -k{n"9a9?
{ aG7QLCL
nEndPos = nStartPos[i+1]; u7>b}+ak&
} D'aq^T'
nEndPos[nEndPos.length-1] = nFileLength; ~LPxVYhK
} ~\tI9L?|A
} -;_`>OU{
6#XB'PR2p
ODK$G [-
//启动子线程 &?^S`V8R*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E 3b`GRay
for(int i=0;i<nStartPos.length;i++) Y)Y`9u<?
{ <@FOqi{o{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Vyv)#32o3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), orn9;|8q
nStartPos,nEndPos,i); oxE'u<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;crQ7}k
fileSplitterFetch.start(); $x5P5^Y
} n(.y_NEgV!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2wE?O^J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]]{$X_0n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D3V5GQ\=
nEndPos = " + nFileLength); 0es[!
// fileSplitterFetch[nPos.length-1].start(); X3#/|>
FL!W oTB
'3Yci(t+
//等待子线程结束 I|lz;i}$
//int count = 0; Z~{0XG\Y
//是否结束while循环 2g1[E_?
boolean breakWhile = false; <A&mc,kj
i"%X[(U7
/_E8'qlx
while(!bStop) LZm6\x
{ @sJ[<V
write_nPos(); `e]L.P_e?
Utility.sleep(500); v4!zB9d
breakWhile = true; t4pc2b
_ngyai1
D.o|pTZ
for(int i=0;i<nStartPos.length;i++) }fnp}L
{ trmCIk&Fkj
if(!fileSplitterFetch.bDownOver) lk{
{ 2?ac\c6"
breakWhile = false; ]Mi ~vG q
break; ?P[uf
} _f$8{&`k
} `m?%{ \
if(breakWhile) `;b@a<Wl
break; {4Y@DQ-
p+U}oC
Z8nj9X$
//count++; k|Vq-w
//if(count>4) Zh`lC1l'
// siteStop(); /]_T
} 1"3|6&=
^RytBwzKM
. $uvQpyh
System.err.println("文件下载结束！"); LziEF-_
} GwxxW
catch(Exception e){e.printStackTrace ();} |cStN[97%
} #}L75
}\}pSqW
`E>HpRcxD
//获得文件长度 L<!}!v5ja
public long getFileSize() ZB GLwe
{ C J S
int nFileLength = -1; _x 'R8/
try{ pkpD1c^
URL url = new URL(siteInfoBean.getSSiteURL()); <m9hM?^q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SV16]Vc
httpConnection.setRequestProperty("User-Agent","NetFox"); j*>+^g\Q6
Kdk0#+xtP
:S}!i?n
int responseCode=httpConnection.getResponseCode(); 0F-X.Dq
if(responseCode>=400) RvKP&
{ $A"kHS7T
processErrorCode(responseCode); ?D-1xnxep
return -2; //-2 represent access is error duB{1
} !/+ZKx("9
i`/_^Fndyu
<uUQ-]QOIh
String sHeader; l CHaRR7
90> (`pI=
3^ ~M7=k
for(int i=1;;i++) By{zX,6'
{ Vrn. #d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qPZ'n=+
//Utility.log(in.readLine()); W)3?T&`
sHeader=httpConnection.getHeaderFieldKey(i); *LpEH,J
if(sHeader!=null) 6s\niro2
{ )orVI5ti
if(sHeader.equals("Content-Length")) 3Yf&F([t
{ ^%|,G:r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M*FUtu
break; P:h;"
} 5ckL=q"+/
} >c%OnA,3
else W[BZ/
break; 5vs~8|aRo
} ~Q"3#4l
} Bz<T{f
catch(IOException e){e.printStackTrace ();} ^T@ (`H4@
catch(Exception e){e.printStackTrace ();} bh|M]*Pq
yQE|FbiA
eznt "Rr2
Utility.log(nFileLength); Hs/ aU_
lo*OmAF
AE`X4q
return nFileLength; i2KN^"v?N
} vdw5T&Q{{C
I|69|^
D/)wg$MI
//保存下载信息（文件指针位置） x8k7y:
private void write_nPos() 's>
{ a5=8zO#%g
try{ W_l/Jpv!W
output = new DataOutputStream(new FileOutputStream(tmpFile)); xY9#ouF
output.writeInt(nStartPos.length); Fb=(FQ2Y?
for(int i=0;i<nStartPos.length;i++) 1BT]_ cP
{ *I6z;.#
// output.writeLong(nPos); n%zW6}
output.writeLong(fileSplitterFetch.nStartPos); OE' ?3S
output.writeLong(fileSplitterFetch.nEndPos); }U3+xl6g
} rx2?y3pv
output.close(); %@ UH,Ew
} hw! l{yv
catch(IOException e){e.printStackTrace ();} /ivcqVu]
catch(Exception e){e.printStackTrace ();} _R&mN\ey5
} yO*~)ALb+
NRu_6~^^
mM&Sq;JJ;
//读取保存的下载信息（文件指针位置） {<&i4;
private void read_nPos() @_s`@,=
{ Ie{98
try{ Z`x|\jI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /jl{~R#1
int nCount = input.readInt(); !>QS746S@
nStartPos = new long[nCount]; fB^h2
nEndPos = new long[nCount]; j6v|D>I
for(int i=0;i<nStartPos.length;i++) -!MrG68
{ [U9b_`
nStartPos = input.readLong(); xi['knUi2-
nEndPos = input.readLong(); VP0q?lh
} MmiC%"7wt
input.close(); wZ6D\I
} rk$&sDc/3
catch(IOException e){e.printStackTrace ();} oV"d%ks
catch(Exception e){e.printStackTrace ();} xxjg)rVuy
} eewhT^
{gh41G;n
AsFn%8_I
private void processErrorCode(int nErrorCode) _CqVH5U?
{ oSVo~F
System.err.println("Error Code : " + nErrorCode); @>`+eg][?P
} nOq?Q
PL$*)#S"$
8B#;ffkmN
//停止文件下载 tLCu7%P>
public void siteStop() u=_"*:}
{ qLrvKoEX2
bStop = true; 58xaVOhb
for(int i=0;i<nStartPos.length;i++) Ku;|Dz/=o
fileSplitterFetch.splitterStop(); HYVSi3[
MKVz'-`u
tGt/=~n9
} hojP3 [
} ]xGo[:k|E
//负责部分文件的抓取 $!Z><&^/
**FileSplitterFetch.java *+(t2!yFmE
*/ s18o,Zs'
package NetFox; lGrp^
;:<z hO
|;xm-AM4r
import java.io.*; )Z6bMAb0'N
import java.net.*; ZEY="pf
\8j5b+
q5 eyle6
public class FileSplitterFetch extends Thread { o95)-Wb
i%BrnjX
+c)"p4m
String sURL; //File URL `=m[(CLb
long nStartPos; //File Snippet Start Position x_za R}WI
long nEndPos; //File Snippet End Position 6,C2PR_+
int nThreadID; //Thread's ID ,RmXZnWY
boolean bDownOver = false; //Downing is over Pdgn9
boolean bStop = false; //Stop identical oCtg{*vp
FileAccessI fileAccessI = null; //File Access interface $cl[Qcw
;]*V6!6RR
/V'^$enK!}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U@t"o3E
{ Xjb 4dip
this.sURL = sURL; 8yW8F26
this.nStartPos = nStart; -64@}Ts*?
this.nEndPos = nEnd; /<[S> ;!kr
nThreadID = id; &6]+a4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~K'e}<-G
} feJzX*u
9Z?P/ o
7D'-^#S5
public void run() /#mq*kNIM6
{ mCM7FFl I
while(nStartPos < nEndPos && !bStop) b1+6I_u.
{ q/T(s
` =ocr8c
-NzO,?
try{ DlC\sm
URL url = new URL(sURL); Zl,c+/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WP(+jL^-
httpConnection.setRequestProperty("User-Agent","NetFox"); 'Cki"4%<
String sProperty = "bytes="+nStartPos+"-"; 'u9,L FO
httpConnection.setRequestProperty("RANGE",sProperty); $~>3bik@
Utility.log(sProperty); a[e&O&Z
hz:^3F`>/&
$'Pn(eZHGv
InputStream input = httpConnection.getInputStream(); q%H`/~AYM
//logResponseHead(httpConnection); G.j R
S8=Am7D]1
$ghAC
byte[] b = new byte[1024]; m(2(Caz{
int nRead; 6d4e~F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7JC^+rk
{ 48}L!m @
nStartPos += fileAccessI.write(b,0,nRead); cb36~{
//if(nThreadID == 1) ZD$W>'m{F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K&L9Ue
} ! z!lQ~
euxkw]`h6
hbZ]DRg
Utility.log("Thread " + nThreadID + " is over!"); Mn)>G36(
bDownOver = true; Oup5LH!sW
//nPos = fileAccessI.write (b,0,nRead); p#14
} 8PN/*Sa
catch(Exception e){e.printStackTrace ();} 0P MF)';R
} "zN2+X"&
} 1yFVF
L#
yQP!Vt^
//打印回应的头信息 aJ!(c}N~97
public void logResponseHead(HttpURLConnection con) xXa* d
{ S7|6dwQ&
for(int i=1;;i++) xg:r5Z/|)
{ 25bbuhss
String header=con.getHeaderFieldKey(i); l7{]jKJue
if(header!=null) f82$_1s^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *HT)Au"5
Utility.log(header+" : "+con.getHeaderField(header)); ?nVwT[
else BIu%A]e"
break; @ve4rc/LI
} Ark+Df/
} 1/ZvcdYB
;Avz%2#c`
YwbRzY-#F
public void splitterStop() d]3c44kkK{
{ j|6@>T1
bStop = true; 6}V)\"u&
} 4=;.<
XwZ~pY ~
WO}l&Q
} {|R@\G.1(
\>B$x@-wg
t^8ii
/* Nu/D$m'PY
**FileAccess.java o+NPe36
*//文件访问(定位，写) 73n|G/9n[
package NetFox; z XI [f
import java.io.*; >"OwdAvX
1q?b?.
L9lNAiOH
public class FileAccessI implements Serializable{ |*G$ilu
dz3KBiq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bCV3h3<
RandomAccessFile oSavedFile; TT85G&#
long nPos; Fi7G S;
'zRi;:UHA
%i!=.7o.
public FileAccessI() throws IOException .Lwp`{F/
{ G,{=sFX
this("",0); OpNTyKbaD
} S":55YQev!
#!A'6SgbkM
qw#wZ'<n
public FileAccessI(String sName,long nPos) throws IOException <yoCW?#
{ sIVVF#0}]
oSavedFile = new RandomAccessFile(sName,"rw"); Q140b;Z
this.nPos = nPos; Sckt gp8
oSavedFile.seek(nPos); DH@]d0N
} O^Y}fo'
=up!lg^M
\d"uR@$3mG
public synchronized int write(byte[] b,int nStart,int nLen) T[~8u9/
{ A#b`{C~l
int n = -1; *btLd7c%
try{ QU#u5sX A
oSavedFile.write(b,nStart,nLen); iY|zv|;]=
n = nLen; {r.KY
} BzVF!<!
catch(IOException e) 4R c_C0O
{ 3?}\Hw
e.printStackTrace (); UQ7E7yY#
} vb&1 S
=XRTeIZ
&Zzd6[G+
return n; +vDEDOS1
} +#B4Z'nT
dy}O6
QbN7sg~~
} slQxz;t
tny^sG/'
L+=pEk_
/* \!*3bR
**SiteInfoBean.java n?UFFi+a
*/ u{asKUce\
package NetFox; 6\+ZTw
jD<fu
M1Frn n
public class SiteInfoBean { %Voq"}}N
Y=NXfTc
;Dw6pmZ
private String sSiteURL; //Site's URL \*wQ%_N5
private String sFilePath; //Saved File's Path `<?{%ja
private String sFileName; //Saved File's Name (TX\vI&
private int nSplitter; //Count of Splited Downloading File u|.c?fW'3
EgYM][:UU
M0B6v}^H
public SiteInfoBean() LH:M`\(DL1
{//nSplitter的缺省值为5 \68x]q[
//default value of nSplitter is 5 Dc1tND$X3g
this("","","",5); 2cB){.E
} <n+]\a97*
x5X;^.1Fr
>qqI6@h]c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Juhi#&`T
{ Mnv2tnU]
sSiteURL= sURL; w!5@PJ)~U
sFilePath = sPath; D*nNu]|j
sFileName = sName; pv}k=wqJ1
this.nSplitter = nSpiltter; t+H=%{z
dj;Zzt3
ZH1W#dt`[
} 3iKy>
\ZOH3`vq
+,g"8&>
public String getSSiteURL() ^xNs^wC.
{ ,A{'lu
return sSiteURL; :xBG~D
} I,nW~;OV0
?*nFz0cs^
9B&fEmgEc?
public void setSSiteURL(String value) W1$<,4j@M
{ HCCEIgCT
sSiteURL = value; +Cf
} lMQ_S"
[9lfR5=Xw[
*l-f">?|
public String getSFilePath() &A1~x!`
{ >l>;"R9N
return sFilePath; }|Ao@UvH
} 4t]YHLBS
<mk'n6B
MS=zG53y
public void setSFilePath(String value) MjNq8'$"
{ d%EUr9~?
sFilePath = value; (v@)nv]U
} zK_+UT
82>90e(CH]
q!OB?03n
public String getSFileName() 1Z$` }a
{ K<g<xW*X
return sFileName; Ofm?`SE*|
} xh90qm
>QcIrq%=
Vzmw%f)_+
public void setSFileName(String value) 7<Yf
{ L3@upb
sFileName = value; d41DcgG'j(
} !Z}d^$
CI}zu;4|
4H]~]?F&
public int getNSplitter() lG>,&(
{ !#[=,'Y
return nSplitter; `a+"[%
} ;/79tlwq
er%D`VHe
)o;oOPT!
public void setNSplitter(int nCount) `zw^ WbCO{
{ Ocp`6Fj
nSplitter = nCount; oZ!1^o3V
} ElK7jWJ+
} ~x #RIt
YTk"'q-
W[R^5{k`
/* [d3i_^\
**Utility.java nl\l7/}6
*/ je[1>\3W
package NetFox; e*Gt%'
2K~<_.S
]}za
public class Utility { JK/VIu&!
*%#Sa~iPo
$-Yq?:
public Utility() q-lejVS(g
{ ?r}'0dW
Ob~7r*q
bZKlQ<sI
} 6]D%|R,Q#}
h@H8oZ[
//线程睡眠 iu$:_W_
public static void sleep(int nSecond) |ler\"Eu
{ !Y95e'f.x
try{ @L/p
Thread.sleep(nSecond); e%wzcn
} {pR4+g
catch(Exception e) ~ 7^#.
{ pFW^
e.printStackTrace (); !!we4tWq
} -H+<81"B#
} dW4FMm>|
tF&g3)D:NV
//日志 %%c1@2G<
public static void log(String sMsg) 0LW|5BVbIO
{ }QzF.![~z
System.err.println(sMsg); Q/2(qD; u
} -KA Y
"pa2,-&
\}p!S$`
public static void log(int sMsg) 1I#]OY#>
{ 0g{`Qd
System.err.println(sMsg); j YVR"D;
} ;NJx9)7<
} cmu|d
p\).zuEf.
m.g2>r`NU
/* [(kC/W)!
**TestMethod.java QrSF1y'd
*/ ,|lDR@
package NetFox; L8WYxJ k
S!@h\3d8{
g7-*WN<
public class TestMethod { W)z@>4`Bb
">|G^@|:A
1.S?(1e"
public TestMethod() E/:mO~1< c
{ ///xx/weblogic60b2_win.exe M!D&a)\
try{ AS-%I+ A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xro%AM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }1}L&M@
SiteFileFetch fileFetch = new SiteFileFetch(bean); g-8D1.U
fileFetch.start(); +!JTEKHKH
} ~e;2gm
catch(Exception e){e.printStackTrace ();} dZ6P)R
6Qw5_V^0o
Py^fWQ5I~%
} +v{g'
|J^}BXW'^)
wOLA8UYW
public static void main(String[] args) ^NB\[ &
{ R[vA%G
new TestMethod(); 0YA
} Po*G/RKu4W
} ?? 2x*l1
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