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)); d=PX}o^
} _r*\ BM8y
for(int i=0;i<nEndPos.length-1;i++) k~^4
{ MQQm3VaKS
nEndPos = nStartPos[i+1]; R7kkth
} ;^5k_\
nEndPos[nEndPos.length-1] = nFileLength; ch8a
} n4/Wd?#`
} `8ac;b
f9W:-00QD
kFv*>>X`
//启动子线程 t$18h2yOL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P[2!D)A
for(int i=0;i<nStartPos.length;i++) T&?g)
{ NOo?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c]PTU2BB8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lPZ(c%P
nStartPos,nEndPos,i); n^Ca?|} ,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5 wrRtzf
fileSplitterFetch.start(); x#J9GP.
} OT%E|) 6'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x9"Cm;H%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HOR8Jwf:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9{*{Ba
nEndPos = " + nFileLength); P.'.KZJ:WD
// fileSplitterFetch[nPos.length-1].start(); @up,5`
%.Ma_4o Z
-B *W^-;*
//等待子线程结束 C9!t&<\}
//int count = 0; bDkZU
//是否结束while循环 iT>u&0B-
boolean breakWhile = false; Aqmpo3P[+
x b"z%.j
:\\NK/"
while(!bStop) :&IHdf0+
{ jYHnJ}<
write_nPos(); H648[H[k
Utility.sleep(500); s-$Wc)l
breakWhile = true; s;BMj^x
>R+-mP!nj
X zJ#)}f
for(int i=0;i<nStartPos.length;i++) {^WK#$]
{ >A$L&8'C
if(!fileSplitterFetch.bDownOver) -&Z!b!jN
{ w+g29
breakWhile = false; y9r4]45
break; >}+{;d
} +e>SK!kB7
} #ibwD:{
if(breakWhile) f#0HiE!
break; ]n!V
Mu\V3`j
T/_u;My;
//count++; BJj'91B[d
//if(count>4) H9mNnZ_k
// siteStop(); E^1yU
} }QFL
YThVG0I =
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System.err.println("文件下载结束！"); ,/\`Rc^n
} oY)eN?c
catch(Exception e){e.printStackTrace ();} h>/teHy /
} ?zW'Hi
A2|Bbqd
KD kGQh#9
//获得文件长度 V<QpC5
public long getFileSize() ~}.C*;J
{ x?Abk
int nFileLength = -1; }r:"X<`
try{ |_;kQ(,
URL url = new URL(siteInfoBean.getSSiteURL()); >Xn,jMUW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e~]P _53
httpConnection.setRequestProperty("User-Agent","NetFox"); I-]G{
]9oj,k
-9b=-K.y
int responseCode=httpConnection.getResponseCode(); 1bFZyD"
if(responseCode>=400) \p4*Q}t
{ cNWmaCLN$
processErrorCode(responseCode); $*C }iJsF
return -2; //-2 represent access is error w2s`9
} h4hAzFQ.s
T3wTMbZ!VK
:zHSy&i`
String sHeader; LT%~Cuf
MhMiSsZ
o?baiOkH
for(int i=1;;i++) [vi =^
{ '12m4quO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S7+>Mk
//Utility.log(in.readLine()); y\FQt];z)
sHeader=httpConnection.getHeaderFieldKey(i); u$\.aWol
if(sHeader!=null) #{6VdWZ
{ xWxHi6U(
if(sHeader.equals("Content-Length")) *~PB
{ mdc?~??8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A;co1,]gR
break; -H60T,o
} +~V%R{h
} 8-;.Ejz!\A
else ,RPb<3 B
break; 7P$*qj~Vh
} ?NoNg^Of
} Otq3nBZ
catch(IOException e){e.printStackTrace ();} IVxJN(N^
catch(Exception e){e.printStackTrace ();} [G_ ;78
4e#g{,
G#7*O`
Utility.log(nFileLength); *).
z 0?MeH#
[J2evi?
return nFileLength; hC$e8t60
} Es[3Ppz
`{#""I^_
AF:_&gF
//保存下载信息（文件指针位置） L'wR$
private void write_nPos() =c6d$
{ gW~YB2 $
try{ a!o%x
output = new DataOutputStream(new FileOutputStream(tmpFile)); rCo}^M4Pb
output.writeInt(nStartPos.length); eEqcAUn
for(int i=0;i<nStartPos.length;i++) 0*MUe1{
{ w"v96%"Y
// output.writeLong(nPos); 8(? &=>@
output.writeLong(fileSplitterFetch.nStartPos); Jq^[^
output.writeLong(fileSplitterFetch.nEndPos); l7t
} (6fD5XtS
output.close(); -c>3|bo
} Sstz_t
catch(IOException e){e.printStackTrace ();} BsA4/Bf
catch(Exception e){e.printStackTrace ();} Bl>m`/\1i
} ;1~n|IY
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5%TSUU+<I
//读取保存的下载信息（文件指针位置） &&;.7E
private void read_nPos() s(X\7Hz_nC
{ m+M^we*R
try{ HL{aqT2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <8(q.
int nCount = input.readInt(); ftn10TO*
nStartPos = new long[nCount]; remc_}`w
nEndPos = new long[nCount]; Eq_@xT0>
for(int i=0;i<nStartPos.length;i++) 24od74\
{ kiF}+,z"
nStartPos = input.readLong(); ",~ZO<P
nEndPos = input.readLong(); $bhI2%_`M
} 'z91aNG]
input.close(); oyiG04H&
} n{W(8K6d@[
catch(IOException e){e.printStackTrace ();} /K2[`+-
catch(Exception e){e.printStackTrace ();} =o~mZ/ 7=M
} c6jVx_tt.
6(7 56
J[}j8x?r
private void processErrorCode(int nErrorCode) +_X*one
{ 7jw+o*;
System.err.println("Error Code : " + nErrorCode); uBG!R#T
} mBL?2~M
*lDVV,T'}w
eJf]"-
//停止文件下载 8A0a/ 7Lj
public void siteStop() wtbN@g0
{ rrC\4#H[??
bStop = true; "7-}#_!g
for(int i=0;i<nStartPos.length;i++) |zRrGQYm
fileSplitterFetch.splitterStop(); BuvnY
~"*W;|)
~APS_iG[
} ShQ!'[J
} +6:
//负责部分文件的抓取 oHfr glGX
**FileSplitterFetch.java _rSwQ<38>
*/ WXo bh
package NetFox; 5ms]Wbh)
g\B ? |%
44 8%yP
import java.io.*; \hBzQ%0
import java.net.*; uju'Bs7
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P\@kqf~pC
public class FileSplitterFetch extends Thread { uNEl]Q]<e]
mY=sh{ir
;P<h9(
String sURL; //File URL UOj*Gt&
long nStartPos; //File Snippet Start Position j0LZ )V
long nEndPos; //File Snippet End Position |)d%3s\
int nThreadID; //Thread's ID k"=*'
boolean bDownOver = false; //Downing is over 2asRJ97qES
boolean bStop = false; //Stop identical tW!*W?
FileAccessI fileAccessI = null; //File Access interface O=LW[h!
Mp js
[zl4"|_`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'Jek< 5
{ !5'4FUlJ
this.sURL = sURL; e)s l
this.nStartPos = nStart; cD9U^SOS
this.nEndPos = nEnd; w3VgGc~
nThreadID = id; Ugo!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1\{FKOt
} AcJrJS)~
HS*Y%*
r=37Q14v
public void run() s-IM
{ tYgHJ~1L*
while(nStartPos < nEndPos && !bStop) /:!l&1l:p
{ K8&) kfyI
!ni 1 qM
'cu14m_
try{ oP T)vN?
URL url = new URL(sURL); ?x 0gI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $v_&jE
httpConnection.setRequestProperty("User-Agent","NetFox"); 48S NI
String sProperty = "bytes="+nStartPos+"-"; yIr0D6L
httpConnection.setRequestProperty("RANGE",sProperty); /]0SF_dZ
Utility.log(sProperty); 2&pE
M*cF'go
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InputStream input = httpConnection.getInputStream(); y5KeUMcu
//logResponseHead(httpConnection); LRaO}-<b
UlNiH
<5Ll<0
byte[] b = new byte[1024]; s1sn,?
int nRead; 7}MnvWP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `t9k!y!GV
{ g[O
nStartPos += fileAccessI.write(b,0,nRead); 7K&Uu3m
//if(nThreadID == 1) @@-TW`G7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]ZP!y
} 2( I4h[
-da: j-_
IMM+g]#e
Utility.log("Thread " + nThreadID + " is over!"); @d^DU5ats>
bDownOver = true; RO3q!+a$/
//nPos = fileAccessI.write (b,0,nRead); |Vlx:
} >hSu1s:
catch(Exception e){e.printStackTrace ();} RX_f[
} ~xDu2-5
} !/a6;:_y
O3T7O`H[
k{S8q?Gc
//打印回应的头信息 C[jX;//Jiu
public void logResponseHead(HttpURLConnection con) ,B_tAg4~
{ o~CEja&(
for(int i=1;;i++) T.')XKP)1N
{ !Ea9 fe
String header=con.getHeaderFieldKey(i); 9 !UNO
if(header!=null) KJS-{ed
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gMZ+kP`
Utility.log(header+" : "+con.getHeaderField(header)); _NwHT`O[
else LXJ;8uW2y
break; 9@IL547V
} NX8hFwR
} WI*CuJU<zJ
8lDb<i
Q}l~n)=
public void splitterStop() lup2>"?*
{ 5}_=q;sZ
bStop = true; tux0}|[^'
} T%FW|jKw
Z]tQmV8e
XHdhSFpm
} f[R~oc5P0
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_!vy|,w@e
/* =-r); d
**FileAccess.java y3j"vKG
*//文件访问(定位，写) d-m.aP)y:
package NetFox; ux!YVvTPd
import java.io.*; ]xoG{%vgb
C4gES"T
mvTp,^1
public class FileAccessI implements Serializable{ qP&:9eL
B/;'D7i|S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %I!2dXNFRF
RandomAccessFile oSavedFile; [dz3k@ >0
long nPos; Rrl
ZQ*Us*9I
;PMh>ZE`
public FileAccessI() throws IOException D*PEIsV
{ S3WUccv
this("",0); j`$$BVZ
} 7Nk|9t
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bi",DKU{l
public FileAccessI(String sName,long nPos) throws IOException lsOfpJ
{ n{etDO
oSavedFile = new RandomAccessFile(sName,"rw"); (dQ=i
this.nPos = nPos; ,d*hhe
oSavedFile.seek(nPos); wsH_pF
} q~W:W}z
bX:h"6{=R
q3h&V
public synchronized int write(byte[] b,int nStart,int nLen) dT?3Q;>B?
{ f^"pZS
int n = -1; nu~]9~)I
try{ $)8,dS
oSavedFile.write(b,nStart,nLen); g3{UP]Z71
n = nLen; gVR]z9
} k 9z9{
catch(IOException e) XQfmD;U
{ tk=S4/VWv
e.printStackTrace (); YOrq)_ l
} 7:b.c
eMFxdtH
@@{5]Y
return n; Qr7v^H~E4.
} 0x]?rd+q8Q
RB%y($
LGZa l&9AY
} NV9JMB{q
%8xRT@Q
|Nj6RB7
/* C&*1H`n
**SiteInfoBean.java [>\|QS|
*/ J,u-)9yBA<
package NetFox; >{:hadUH
dY~z6bT
p)?6#~9$
public class SiteInfoBean { EEL3~H{(
S7PWP<9
sO6=w%l^
private String sSiteURL; //Site's URL yrfV&C%=n
private String sFilePath; //Saved File's Path r@Jy*2[-Jq
private String sFileName; //Saved File's Name Yb/*2iWX
private int nSplitter; //Count of Splited Downloading File 9`Fw}yAt
s<k2vbhI
vPz7*w
public SiteInfoBean() x(eX.>o\
{//nSplitter的缺省值为5 ^IIy>
//default value of nSplitter is 5 v}V[sIs}
this("","","",5); nM b@ B
} l$EN7^%w
"opMS/a"7
dpNERc5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p@4GI[4
{ 0NC70+4L
sSiteURL= sURL; 7dACbqba
sFilePath = sPath; pb)8?1O|s
sFileName = sName; (?JdiY/
this.nSplitter = nSpiltter; bDtb6hL
,%l}TSs
X~JP 1
} foQo`}"5
7>F{.\Z
+>vKI8g*RH
public String getSSiteURL() * zyik[o
{ )hj:Xpj9#
return sSiteURL; E BBd
} 4m1r@ $
KAFR.h:p9
~tW~%]bs2Q
public void setSSiteURL(String value) mOn_#2=KF
{ sTlel&
sSiteURL = value; ja';NIO-
} B#SVN Lv
(A6~mi r!
T:Klr=&V
public String getSFilePath() IY#:v%U
{ 9N}\>L)_
return sFilePath; 5Q"w{ n
} {o)pwM"@(
.\^0RyJE
Hy[: _E
public void setSFilePath(String value) M%!;5
{ D5?8`U m=
sFilePath = value; oYStf5
} x}?<9(nE c
lYQ|NL():
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public String getSFileName() KBN% TqH|
{ 9T24dofkJ
return sFileName; sEdz`F
} vb6EO[e%I
F1L[3D^-
!!^z6jpvn
public void setSFileName(String value) <dH@e
{ Q,xL8i M,
sFileName = value; l_+@Xpl
} x2#JD|0
p#ar`-vQ
}:ZA)
public int getNSplitter() 7D#y
{ iT4*~(p 3
return nSplitter; bhpku=ov
} U-u?oU-.'
)P:^A9&_n=
H,X|-B
public void setNSplitter(int nCount) 0Lxz?R x]<
{ 8v& \F
nSplitter = nCount; rXX>I;`&
} 6&eXQl
} :V)jm`)#+
cu0IFNF}[
=79R;|5
/* P6 OnE18n
**Utility.java JF4A
*/ -Qn7+?P
package NetFox; ]19VEH
2L^)k?9>g+
@ivd|*?k0
public class Utility { L9D`hefz
_]>1(8_N
FI$:R
public Utility() 'RK"/ZhqE
{ PX 8UVA
r<e%;S
5XZ!yYB?
} @%R<3!3v
'+cI W(F?
//线程睡眠 y~ =H`PAE
public static void sleep(int nSecond) `um,S
{ ssi7)0
try{ MePD:;mm^
Thread.sleep(nSecond); $>XeC}"x68
} ~t`s&t'c|
catch(Exception e) ?0VR2Yb${b
{ yJm"vN
e.printStackTrace (); c[dzO.~
} ]yU"J:/
} HB/V4ki
WVbrbs4
//日志 fSuykbZ
public static void log(String sMsg) "#j}F u_!
{ B )r-,M
System.err.println(sMsg); A IP~A]T
} az(<<2=
PLyity-L[7
\n)',4mY
public static void log(int sMsg) 9B: 3Ha=
{ iEr,ly
System.err.println(sMsg); []>'Dw_r
} kz"uTJK
} 9Yx(u2PQ
)u)=@@k21
&7aWVKon
/* e`D}[G#
**TestMethod.java /~[Lr
*/ 6Xlzdt
package NetFox; o%$.8)B9F
9)q3cjP{<
5AYOM=O]t
public class TestMethod { %a;#]d
RdTM5ANT
i--t ?@#
public TestMethod() NK_|h%
{ ///xx/weblogic60b2_win.exe {m.$EoS
try{ <>cS@V5j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }rTH<!j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?{{w[U6NE
SiteFileFetch fileFetch = new SiteFileFetch(bean); 200yN+ec
fileFetch.start(); ~U9K<_U
} 'ZfgCu)St
catch(Exception e){e.printStackTrace ();} Ey46JO"
c3A\~tHW
m~ tvuz I
} SUncQJJ0S*
:d36oiHKu
7F^d-
public static void main(String[] args) 3$$E0`7.
{ K7+yU3
new TestMethod(); h+f>#O+:
} 0B NLTRv
} xt{'Be&Ya+
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