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)); L.S;J[a;
} " @v <Bk
for(int i=0;i<nEndPos.length-1;i++) p<,*3huj
{ /5Oa,NS7
nEndPos = nStartPos[i+1]; 1*9U1\z
} }]lr>"~y}
nEndPos[nEndPos.length-1] = nFileLength; d$ x"/A]<
} gm igsXQ
} Z -W(l<
>[*8I\*@n
ykV 5
//启动子线程 05b_)&4R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A v2 08}Y
for(int i=0;i<nStartPos.length;i++) "1L$|
{ 0n;< ge&~R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;"dV"W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]G5w6&d
nStartPos,nEndPos,i); h*w%jdQ6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %oZ6l*
fileSplitterFetch.start(); 925|bX6I
} }BZ"S-hZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KKiE@_z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E4|jOz^j4\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w5Ay)lz
nEndPos = " + nFileLength); BD_Iz A<wK
// fileSplitterFetch[nPos.length-1].start(); .Le?T&_
WtG~('g>&
@+Si?8\
//等待子线程结束 $\]&rZVi
//int count = 0; El.hu%#n*G
//是否结束while循环 C8Qa$._
boolean breakWhile = false; ]rWgSID
S|7!{}
zgNc4B
while(!bStop) zNxW'?0Z?
{ c:<005\Bg
write_nPos(); kEOS{C%6R
Utility.sleep(500); "B3N*R(["
breakWhile = true; JBE!j-F
mS(fgq6
UNom-
for(int i=0;i<nStartPos.length;i++) r:f[mk"-"A
{ S- pV_Ff
if(!fileSplitterFetch.bDownOver) K/i*w<aPb7
{ `6lr4Kk @R
breakWhile = false; NG "C&v
break; r'^Hg/Jzt
} 6kpg+{;
} * w?N{.
if(breakWhile) kYG/@7f/
break; jQ2Ot<
gtk7)Uh
e1%/26\
//count++; 5*lT.
//if(count>4) [N7{WSZ&
// siteStop(); CE#gfP
} F`gi_;c
VH9dleZ
/{+y2.{j
System.err.println("文件下载结束！"); D8Ykg >B;&
} 95 ;x=ju
catch(Exception e){e.printStackTrace ();} B@&4i?yJ
} M?Dfu .t
DI:]GED"=
QZ6D7tUc8
//获得文件长度 '*5i)^
public long getFileSize() _F>CBG
{ \fG#7_wt
int nFileLength = -1; =]6%G7T
try{ +x0!*3q
URL url = new URL(siteInfoBean.getSSiteURL()); L^}_~PO N5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iII=;:p
httpConnection.setRequestProperty("User-Agent","NetFox"); )wC?T
}&cu/o4
(gP)%
int responseCode=httpConnection.getResponseCode(); ^ DaBz\
if(responseCode>=400) kW;+|qs^
{ QRHu3w
processErrorCode(responseCode); NW]Lj>0Y
return -2; //-2 represent access is error '[AlhBX
} w>pq+og&
\-h%O jf4
XGYbnZ~
String sHeader; RL!Oi|8
)J2mM
gbF+WE
for(int i=1;;i++) ?}wk.gt>
{ #M9~L[nFS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "I3@m%qv
//Utility.log(in.readLine()); ?zh9d%R
sHeader=httpConnection.getHeaderFieldKey(i); A\4D79>x
if(sHeader!=null) $xzAv{
{ #.rdQ,)<
if(sHeader.equals("Content-Length")) ojaws+(& y
{ >_[9t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yA)/Q Yge
break; \pPY37l
} 01wX`"I
} EMY/~bQW
else idLWe9gC
break; 6 Q%jA7
} fObg3S92
} v- 2:(IV
catch(IOException e){e.printStackTrace ();} nV"~-On
catch(Exception e){e.printStackTrace ();} e>6y%v;
((H^2KJn
t<#TJ>Le
Utility.log(nFileLength); th
O#ai)e_uQk
kVkU)hqR
return nFileLength; xN5)
} n&$j0k
6HT;#Znn
.YhA@8nc~l
//保存下载信息（文件指针位置） CDsSrKhx
private void write_nPos() Jl(&!?j
{ :ci5r;^
try{ \hTm)-FP
output = new DataOutputStream(new FileOutputStream(tmpFile)); m8A#~i .
output.writeInt(nStartPos.length); 6eLR2
for(int i=0;i<nStartPos.length;i++) %Qmn-uZ
{ ;D3C>7y
// output.writeLong(nPos); gwLf'
output.writeLong(fileSplitterFetch.nStartPos); YmL06<Mh
output.writeLong(fileSplitterFetch.nEndPos); NP0\i1P>.?
} Px4)>/ z,
output.close(); i6^twK)j
} }JF13beU
catch(IOException e){e.printStackTrace ();} U;YC}r
catch(Exception e){e.printStackTrace ();} [$mHv,~
} {#ZlM
*:Y%HAy*
RSfQNc9Z
//读取保存的下载信息（文件指针位置） <^VJy5>
private void read_nPos() [)H&'5 +F
{ ,|3MG",@@h
try{ D9<!mH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N4v~;;@(
int nCount = input.readInt(); Y\D!/T
nStartPos = new long[nCount]; n`#tKwWHYx
nEndPos = new long[nCount]; H=<S 9M
for(int i=0;i<nStartPos.length;i++) ,vr? 2k
{ HJ9Kz^TnC
nStartPos = input.readLong(); t_o['F
nEndPos = input.readLong(); m4**~xfC
} ~5NXd)2+Ks
input.close(); Zq^At+8+
} +[M6X} TQ
catch(IOException e){e.printStackTrace ();} .!Oo|m`V@
catch(Exception e){e.printStackTrace ();} R cAwrsd
} h?AS{`.1
UbXh,QEG*
{&cJDqz5=
private void processErrorCode(int nErrorCode) ^NRl//
{ &q3"g*q
System.err.println("Error Code : " + nErrorCode); FEW14U'O
} '9laa=H%8
fa-IhB1!K
qB~rQPa
//停止文件下载 \z>fb%YW
public void siteStop() `nUXDmdwzO
{ ),0g~'I~D
bStop = true; v_BcTzQ0S
for(int i=0;i<nStartPos.length;i++) @:j}Jmg
fileSplitterFetch.splitterStop(); TITKj?*o
*F+KqZ.2
lG9bLiFY
} eX?OYDDC0j
} Tl%`P_J)-S
//负责部分文件的抓取 02f~En}>6
**FileSplitterFetch.java 4QH3fTv
*/ ;!=G
package NetFox; ,$@bE
.7Dtm<K#
lsJSYJG&
import java.io.*; ojafy}
import java.net.*; A0/"&Ag]
lAS#874dE
9Z|jxy
public class FileSplitterFetch extends Thread { rx'RSo#1O
!`k1:@NZ
- \5v^l
String sURL; //File URL O@tU.5*$5
long nStartPos; //File Snippet Start Position RM]\+BK
long nEndPos; //File Snippet End Position fFMlDg[];
int nThreadID; //Thread's ID 2L:_rR#w
boolean bDownOver = false; //Downing is over `[z<4"Os
boolean bStop = false; //Stop identical KT_!d*
FileAccessI fileAccessI = null; //File Access interface SOs:]U-T3
v]'ztFA
/'Ass(=6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7TgOK
{ }K7#Q
this.sURL = sURL; GD&uQ`Y5
this.nStartPos = nStart; .!Qki@
this.nEndPos = nEnd; Za/-i"U
nThreadID = id; /@wg>&L]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bENdMH";
} bZ?v-fn\D,
+M./@U*g
_ q(ko/T
public void run() j:^#rFD4?
{ 9`T)@Uj2n
while(nStartPos < nEndPos && !bStop) bbtGXfI+SB
{ 18)'c?^.
+dWDxguE{w
Y4OPEo5o
try{ e{h<g>7
URL url = new URL(sURL); [/PR\'|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ")_|69 VX
httpConnection.setRequestProperty("User-Agent","NetFox"); Hu^1[#
String sProperty = "bytes="+nStartPos+"-"; ls?~+\Jb
httpConnection.setRequestProperty("RANGE",sProperty); 3oBtP<yG.
Utility.log(sProperty); $'0u|Xy`
:I"2V
I.WvLLK2
InputStream input = httpConnection.getInputStream(); XQrF4l
//logResponseHead(httpConnection); vV'EZ?
ob+b<HFv
aB*Bz]5;E
byte[] b = new byte[1024]; Htay-PB }
int nRead; ynmWW^dg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <>n0arAn
{ >Y&N8PHD
nStartPos += fileAccessI.write(b,0,nRead); dah[:rP,n{
//if(nThreadID == 1) b1?#81
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); teOe#*
} s6ZuM/Q
QgrpBG
\n"{qfn`r
Utility.log("Thread " + nThreadID + " is over!"); j>*S5y.{
bDownOver = true; 3RiWZN
//nPos = fileAccessI.write (b,0,nRead); iMt:9|yF}8
} pe0F0Ruy
catch(Exception e){e.printStackTrace ();} v&Ii^?CvO
} f& 0M*o,)
} qsF<!'m7`
wJg1Y0nh
)) Zf|86N
//打印回应的头信息 >lmi@UN|k
public void logResponseHead(HttpURLConnection con) +ylTGSZS
{ PUz*!9HC
for(int i=1;;i++) ZufR{^W
{ OGBHos
String header=con.getHeaderFieldKey(i); "HX<,l8f%
if(header!=null) 3ovWwZ8&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ];}Wfl
Utility.log(header+" : "+con.getHeaderField(header)); Q;MT"=RW
else t$+?6E
break; @M<|:Z %.@
} 7@C<oy_bb
} x9NEFtqjm
".f ;+wH
xpNH?#&
public void splitterStop() u=Fv2
{ +~St !QV%
bStop = true; 2:*w~|6>}5
} i}b${no
r~[Ia!U?
f'8kish
} 6f;fx}y
3yANv?$a
-1Jg?cPzk
/* +O'3|M
**FileAccess.java {Z{75}
*//文件访问(定位，写) TH)"wNa
package NetFox; hrmut*<|
import java.io.*; yhlFFbU
OL5v).Bb
wWgWWXGT}
public class FileAccessI implements Serializable{ 9K/HO!z
m2-Sx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s.EI`*xylY
RandomAccessFile oSavedFile; k[0-CB
long nPos; (VS5V31"
?xK8#
;g8R4!J
public FileAccessI() throws IOException so^lb?g
{ U!T~!C^
this("",0); WJ)z6m]
} w'L\?pI
mrTlXXz
A+HF@Uw}^
public FileAccessI(String sName,long nPos) throws IOException \Fl+\?~D
{ h"lX4
oSavedFile = new RandomAccessFile(sName,"rw"); :WQ^j!9'
this.nPos = nPos; ko1J094Y%
oSavedFile.seek(nPos); 0,r}o
} tzZ63@cm
^F>cp ,x
z25lZI" X`
public synchronized int write(byte[] b,int nStart,int nLen) {-ZFp
{ CPgCjtY
int n = -1; Yaj0;Lo[wt
try{ INUG*JC6
oSavedFile.write(b,nStart,nLen); =b38(\
n = nLen; U0=]
} "ZHW2l Mf
catch(IOException e) Cv }Qwy
{ "~`I::'c
e.printStackTrace (); Z.d7U~_
} FE" y\2}
- *F(7$
Kqun^"Df
return n; R=.4
} S2n39 3
yPM3a7-Bm
]FD'5p{
} t'9*R7=
u?>B)PW
N03G>fZ
/* R,)}>X|<
**SiteInfoBean.java Xm+8
*/ 'iy*^A `Y
package NetFox; 0$_oT;{8
YiYV>gaf"H
*ohL&'y
public class SiteInfoBean { 5pU2|Bk /
5'0xz.)!
+$X#q8j06
private String sSiteURL; //Site's URL !) S ?m
private String sFilePath; //Saved File's Path ~n[d4qV&
private String sFileName; //Saved File's Name CQZgMY1{
private int nSplitter; //Count of Splited Downloading File Mmj;'iYOwF
Y^36>1.:
K6y :mJYp\
public SiteInfoBean() Jwj%_<
{//nSplitter的缺省值为5 np%\&CVhN
//default value of nSplitter is 5 y+!+ D[x
this("","","",5); JBZUv
} *J$=.fF1
$=5=NuX
BQBeo&n6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F&])P- !3
{ c<uN"/gi*
sSiteURL= sURL; bB }$'
sFilePath = sPath; lAzjN~V
sFileName = sName; h tx;8:
this.nSplitter = nSpiltter; YWMGB#=
,REJt
V<D.sd<
} /y A7%2
!E,A7s
KQ`qpX^d
public String getSSiteURL() _8Z_`@0
{ j>]nK~[ka
return sSiteURL; kgy:Q'
} 4VHqBQ4
PGYXhwOI
.w> 4
public void setSSiteURL(String value) n"+[ :w4
{ /R~1Zj2&
sSiteURL = value; k4,BNJt'Z
} ?6(I V]
UJ0<%^f
-6Oz^
public String getSFilePath() 6&DX] [G
{ i O/K nH
return sFilePath; 4Y,R-+f
} {n/uh0>f*
;l&4V
I/M_p^
public void setSFilePath(String value) 4 SHU
{ Rop'e8Q
sFilePath = value; ZIPl7tTw
} rSxxH]-
{g2@6ct
#?*WPq
public String getSFileName() pAb.c
{ NM]s8cK_
return sFileName; _$wmI/_JM
} WuPH'4b 5
?6L&WB
rEHkw '
public void setSFileName(String value) ^zEwA
{ F^N82
sFileName = value; ]Pry>N3G5
} h@:TpE+N
Ct2j ZqCDo
{88gW\GL
public int getNSplitter() UbEb&9}
{ CPVjmRUF|
return nSplitter; lY~4'8^
} HS{(v;
*+TH#EL2
} X^|$
public void setNSplitter(int nCount) "jTKSgv+q5
{ nL$x|}XAcj
nSplitter = nCount; :ml2.vP
} \Y|~2Ls8tu
} 'eo KZX+
i<H wTmm$
.!1S[
/* G2]4n T
**Utility.java Z|_K6v/c
*/ GwG4LIp
package NetFox; Eo\UAc
'" X_B0k
!(n4|Wd
public class Utility { V[}4L|ad
>N;F8v
Ypeiy`.
public Utility() }tH[[4tw,
{ nSF``pp+
uch>AuF:
p8kr/uMP ;
} R)M_|ca
f6_];]yP
//线程睡眠 Xcrk;!IB?
public static void sleep(int nSecond) pM{nh00[
{ f;&]:2.j
try{ bHhtd_}
Thread.sleep(nSecond); V?P,&c?84
} ~by]xE1Eg
catch(Exception e) Cw~RJ^a_
{ 1iX)d)(b
e.printStackTrace (); PzV@umC1#f
} B|C/ Rk6?
} +$$$
Py>{t4;S
//日志 `+zWu55;
public static void log(String sMsg) >iOzl wmG
{ /0W9g
System.err.println(sMsg); y kW [B
} *?z0$Kz<,[
qS/V"|G(
4B4Z])$3
public static void log(int sMsg) s0*0 'f
{ L4b:F0
System.err.println(sMsg); ) c/% NiN
} < -uc."6\
} i.xXb[M+
$xOI 1|d
9%iUG(DC
/* `C_jP|[e
**TestMethod.java BnCKSg7V
*/ Tx1vL
package NetFox; ?E9DXg
&O)&k
?9HhG?_x
public class TestMethod { RP2_l$
ari7iF~j
^A][)*SZ
public TestMethod() YXU|h
{ ///xx/weblogic60b2_win.exe $B#6tk~u
try{ b1gaj"]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Fhv2V,nZ<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T1`|~Z?g-
SiteFileFetch fileFetch = new SiteFileFetch(bean); C@Nv;;AlU
fileFetch.start(); +&X%<S W
} -w;(cE
catch(Exception e){e.printStackTrace ();} 2>]a)
T/c<23i
!Oj)B1gc6&
} K.%U
'`|AI:L
FVB;\'/
public static void main(String[] args) \eGKkSy
{ @)>D))+
new TestMethod(); P_gYz!
} zf.-I
} H{?9CxYa
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