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)); MVnN0K4
} >23$_'2
for(int i=0;i<nEndPos.length-1;i++) *|<T@BXn
{ IU<lF)PF$
nEndPos = nStartPos[i+1]; (i L*1f
} 8v z h5,U
nEndPos[nEndPos.length-1] = nFileLength; D Qz+t
} k3H0$1
} DF_wMv:>^
=&6sU{j*
.%y'q!?
//启动子线程 ;>>n#8`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Th$Z9+()
for(int i=0;i<nStartPos.length;i++) @R}3f6@67
{ |_+#&x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <#J5.I 1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OLPY<ax
nStartPos,nEndPos,i); $[}EV(#y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <}:` Y"
fileSplitterFetch.start(); z3]W #
} d!w3LwZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u7^(?"x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;W+8X-B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 63 'X#S
nEndPos = " + nFileLength); MT"&|Og
// fileSplitterFetch[nPos.length-1].start(); )=sbrCl,C/
=6qTz3t
X3a9-
//等待子线程结束 *2u~5Kc<
//int count = 0; BGBHA"5fz
//是否结束while循环 mM72>1~L*
boolean breakWhile = false; PWyf3
~x!up9
A$r$g\5+
while(!bStop) qxb]UV,R
{ oWL_Hh%-f`
write_nPos(); DrKB;6
Utility.sleep(500); H)i|?3Ip
breakWhile = true; "5Y6.$Cuf!
?!&%-R6*
C&>*~
for(int i=0;i<nStartPos.length;i++) @`dg:P*[
{ GE(~d'
if(!fileSplitterFetch.bDownOver) 3PGAUQR#"q
{ _<LL@IX
breakWhile = false; @U18Dj[
break; MNWI%*0LO
} Fu_I0z
} VK]U*V1
if(breakWhile) UL-_z++G
break; sa4w.9O1GS
J6n>{iE
T"[]'|'
//count++; HB8s[]A:D
//if(count>4) .dk<?BI#H
// siteStop(); 7Vsp<s9bj
} HK8sn1j
gr SF}y!3
m9oOH5@K~
System.err.println("文件下载结束！"); H:]cBk^[,
} {?eUAB<
catch(Exception e){e.printStackTrace ();} RC/ 3\'
} 3}<U'%sd
zk FX[-'O
N=BG0t$
//获得文件长度 (_zlCHB
public long getFileSize() A vq+s.h
{ >< $LV&
int nFileLength = -1; WA8<:#{e
try{ @wgd 3BU
URL url = new URL(siteInfoBean.getSSiteURL()); ]~I+d/k d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~_vSMX
httpConnection.setRequestProperty("User-Agent","NetFox"); Ztg_='n
\~ChbPnc
\"oZ\_
int responseCode=httpConnection.getResponseCode(); x{SlJ%V
if(responseCode>=400) T:$^1"\
{ WJOoDS!i
processErrorCode(responseCode); (MI>7| ';
return -2; //-2 represent access is error \4q|Qno8
} qK a}O*
GYfOwV!zB
[|OII!"
String sHeader; P[WkW#
HCs^?s8Pp
+QU>D:l
for(int i=1;;i++) Sp80xV_B
{ (c(F1=K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZpVkgX4
//Utility.log(in.readLine()); rk W7;!
sHeader=httpConnection.getHeaderFieldKey(i); >\Dy
if(sHeader!=null) z}ar$}T
{ cK+TE8ao
if(sHeader.equals("Content-Length")) 93HVx#
{ P>C'?'Q7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i=aR~
break; ,2nu*+6Y/
} &/? Ct!_
} l~rj7f;
else }_]AQN$'G
break; e{5?+6KH
} Or5?Gt
} [j+:2@
catch(IOException e){e.printStackTrace ();} 1IA1;
catch(Exception e){e.printStackTrace ();} :3n@].
y("WnVI
;>v.(0FE6
Utility.log(nFileLength); /h0bBP
k{SGbC1=VK
=0=#M(w
return nFileLength; q@ -B+
} PC_!
'w+]kt-
=\oH= f
//保存下载信息（文件指针位置） b# N"}-\^
private void write_nPos() Sf*)Z3f
{ OoSk^U)
try{ dH^6K0J
output = new DataOutputStream(new FileOutputStream(tmpFile)); !CGX\cvW
output.writeInt(nStartPos.length); VI2lwE3
for(int i=0;i<nStartPos.length;i++) hpAdoy[
{ r%PWv0z_c
// output.writeLong(nPos); :(n<c
output.writeLong(fileSplitterFetch.nStartPos); I}4 PB+yu
output.writeLong(fileSplitterFetch.nEndPos); zuvPV{ X
} zqeQ
output.close(); j>\c >U
} r<UVO$N
catch(IOException e){e.printStackTrace ();} o&?c,FwN
catch(Exception e){e.printStackTrace ();} <b:%o^
} Hb=#`
jSY[Y:6md
VsQ|t/|#
//读取保存的下载信息（文件指针位置） ] 3{t}qY$A
private void read_nPos() 5*YoK)2J
{ f^$,;
try{ PftK>,+,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $o[-xNn1
int nCount = input.readInt(); 0|P=S|%~
nStartPos = new long[nCount]; KZppQ0
nEndPos = new long[nCount]; c{MoeIG)v@
for(int i=0;i<nStartPos.length;i++) b(*\4n
{ +0pI}a\
nStartPos = input.readLong(); QL/KY G
nEndPos = input.readLong(); 68tyWd}
} UM7@c7B?
input.close(); o<Zlm)"%1
} 9{u8fDm!
catch(IOException e){e.printStackTrace ();} 8rsc@]W
catch(Exception e){e.printStackTrace ();} 9M96$i`P
} 'c35%?]
],]Rv#`
cJ4My#w
private void processErrorCode(int nErrorCode) o:d7IL
{ ?@b6(f xX
System.err.println("Error Code : " + nErrorCode); h*S"]ye5
} -n _Y.~
LDlYLsF9
rqamBm 5
//停止文件下载 #1<m\z7l
public void siteStop() t+?Bb7p,H
{ W'./p"2g
bStop = true; .|,LBc!
for(int i=0;i<nStartPos.length;i++) UleT9 [M
fileSplitterFetch.splitterStop(); $BwWQ?lp
hi8q?4jE
;+hh|NiQ
} %SmOP sz
} Cj0r2^`
//负责部分文件的抓取 ^j<v~GTx+
**FileSplitterFetch.java ,->ihxf
*/ {T4_Xn-I
package NetFox; /@9Q:'P
pv]@}+<Dt
g NI1W@)
import java.io.*; t ed:]
import java.net.*; zj`c%9N+
^#_gk uyd!
Px_8lB/;
public class FileSplitterFetch extends Thread { >dAl*T
#HcQ*BiF3
,P~e)<.
String sURL; //File URL J}V4.R5d
long nStartPos; //File Snippet Start Position aq?bI:>8
long nEndPos; //File Snippet End Position 9)!Ksg(h
int nThreadID; //Thread's ID AwJg/VBo)
boolean bDownOver = false; //Downing is over xQFRM aQE
boolean bStop = false; //Stop identical 5{! fa
FileAccessI fileAccessI = null; //File Access interface r^,_m,s'<
b<u\THy#
eb_.@.a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .}dLqw
{ 7U [C=NL
this.sURL = sURL; j7P49{
this.nStartPos = nStart; ~^F]t$rz
this.nEndPos = nEnd; |O8e;v72g^
nThreadID = id; 0LQRQuh1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #}~tTL
} 9wL2NC31Q
^%\a,~
,+i^]yF3j
public void run() nDrRK
{ RZz?_1'
while(nStartPos < nEndPos && !bStop) iA[T'+.Y
{ fG2)r
>{^_]phlb
!.R-|<2|6
try{ neEqw+#Z
URL url = new URL(sURL); BValU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ( fFrX_K]
httpConnection.setRequestProperty("User-Agent","NetFox"); |gk*{3~y
String sProperty = "bytes="+nStartPos+"-"; OS[ s Qo5
httpConnection.setRequestProperty("RANGE",sProperty); ?qQ{]_q1&.
Utility.log(sProperty); `q}D#0
i@/%E~W
*JOK8[Qn
InputStream input = httpConnection.getInputStream(); 1RkN^FZOxq
//logResponseHead(httpConnection); Trirb'qO
m-{DhJV
L4iWR/&
byte[] b = new byte[1024]; whI4@#
int nRead; R&uPoY,f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7] y3<t
{ /qQx~doK
nStartPos += fileAccessI.write(b,0,nRead); |6AR!
//if(nThreadID == 1) icG 9x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P}6#s'07~
} Dk\%,[4(
IQBL;=.J.
:lu!%p<$
Utility.log("Thread " + nThreadID + " is over!"); 4f j}d.?
bDownOver = true; orJ|Q3c)d
//nPos = fileAccessI.write (b,0,nRead); hTBJ\1 -
} ]Jz=.F sO
catch(Exception e){e.printStackTrace ();} ` k] TOc
} &tOo[U?
} 9^Xndo]y
+9HU&gQ3
U'jmgHq
//打印回应的头信息 k2Q[v
public void logResponseHead(HttpURLConnection con) R5sEQ| E
{ C5=^cH8
for(int i=1;;i++) )F9IzR-&m
{ Qe~C}j%
String header=con.getHeaderFieldKey(i); #|\|G3Si %
if(header!=null) WGV]O|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {Lju7'5L
Utility.log(header+" : "+con.getHeaderField(header)); 3\2&?VAjR
else >(:3H+
break; 55v=Ij?M
} TrDTay
} IiKU=^~w
B)k/]vz)*D
!5 S#
public void splitterStop() T:j41`g%s
{ i(A`'V8GY
bStop = true; <,Gjo]z
} %YxKWZ/?
u9_?c G-
k1[`2k:Hk
} e,XT(KY
Q*1Avy6]
li3X}
/* (fc_V[(m"
**FileAccess.java UHJro9
*//文件访问(定位，写) ZV Ko$q:F
package NetFox; ycN!N
import java.io.*; PR;Bxy
FUI/ A>
V^(W)\
public class FileAccessI implements Serializable{ 5P*jGOg.
319 4]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `~axOp9N
RandomAccessFile oSavedFile; @>`N%wH'
long nPos; FkMM>X
6heK8*.T
H( LK}[
public FileAccessI() throws IOException dnANlNMk?
{ xfUV'=~(
this("",0); ILG&l<!E
} e23&d
"dG*HKrr
6\h*SBI?(
public FileAccessI(String sName,long nPos) throws IOException :CM2kh"Iu
{ _576Qa'rm
oSavedFile = new RandomAccessFile(sName,"rw"); h6Vd<sV\tf
this.nPos = nPos; a;i}<n7
oSavedFile.seek(nPos); =)#XZ[#F
} B"7~[,he
a#0*#&?7@
&w_8E+YZ
public synchronized int write(byte[] b,int nStart,int nLen) y=GDuU%
{ BAqwYWdS
int n = -1; jp-(n z\
try{ 9aID&b+
oSavedFile.write(b,nStart,nLen); z#5qI',L
n = nLen; rl"yE=
} /0L]Pf;
catch(IOException e) .ErR-p=-
{ ^b&hy&ag
e.printStackTrace (); hzV%QDUpe
} p,4S?cr>a
kaZcYuT.9
gYL#} )g
return n; &S^a_L:
} H8c -/
|$T?P*pI.
f]+. i-c=
} LNgFk%EH
+SFo2Wdr43
8LtkP&Wx
/* Lz-(1~o
**SiteInfoBean.java 17rg!'+
*/ 5Shc$Awc!
package NetFox; ,=6;dT
neWx-O
Dk~ JH9#
public class SiteInfoBean { `C:J{`
)q7!CG'oY
f+Bv8 g
private String sSiteURL; //Site's URL N[=R$1\Z
private String sFilePath; //Saved File's Path o`jVd,aj
private String sFileName; //Saved File's Name BBoVn^Z*R
private int nSplitter; //Count of Splited Downloading File !O,`Z`T?
)q+;+J`>
E-rGOm" m
public SiteInfoBean() =HoA2,R)
{//nSplitter的缺省值为5 M/6q ^*
//default value of nSplitter is 5 ()$tP3o
this("","","",5); r-}C !aF]
} }8'bXG+
i/DUB<>p6
}5gQ dj[Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CIt@xi#I
{ Cp-p7g0wlg
sSiteURL= sURL; } AHR7mu=
sFilePath = sPath; Daf;; w
sFileName = sName; &W y9%
this.nSplitter = nSpiltter; 2)`4(38
0o!Egq_
$T'lWD*
} [{-;cpM\
{Pi]i?
,3ivB8
public String getSSiteURL() nrZZkQNI
{ A3e83g~L
return sSiteURL; XuW>GT/
} Pu]Pp`SP
n ^C"v6X
SnW>`
public void setSSiteURL(String value) _$qH\>se
{ LT '2446
sSiteURL = value; ?F%,d{^
} 2G`tS=Un
~LN {5zg
AtlUxFX0S
public String getSFilePath() Rp""&0
{ ~d6zpQf7>
return sFilePath; RC]-9gd3Q
} Hn,;G`{
^&8xfI6?
w`K=J!5y2g
public void setSFilePath(String value) -6>T0-
{ 7%^/Jm
sFilePath = value; ^5*9BwH`
} ||kUi=5
|Xk>a7X
odpjEeQC
public String getSFileName() vZt48g
{ 6<C|O-
return sFileName; _QOZ`st
} t2q{;d~.
Dj@7vM%_
;bt%TxuKb
public void setSFileName(String value) 0)-yLfTn
{ zH+a*R
sFileName = value; 3At%TA:
} %FO#j6
iyf vcKO
3N5b3F
public int getNSplitter() qUtlh,4)
{ 7^Q4?(A
return nSplitter; c'~6 1HA<
} UB1/0o
J9*$@&@S
6` @4i'.
public void setNSplitter(int nCount) \$[S=&E
{ N1i%b,:3
nSplitter = nCount; etWCMR
} iqPMCOPZ
} zU,Qph ,<
K.K=\ Y2
uMe]].04
/* i_6 Y6
**Utility.java #)N}F/Od^
*/ 5WvtvSO
package NetFox; W #kOcw
R<n'v.~"A
xF8^#J6>
public class Utility { 0'0GAh2
"WE*ED
fTg^~XmJ
public Utility() +GqUI~a
{ hMvLx>q3)
^9*kZV<K
Pwg?a
} 0B?t:XU,
TmIw?#q^
//线程睡眠 :N ~A7@
public static void sleep(int nSecond) L1J~D?q
{ Y<0R5rO
try{ .8EaFEd
Thread.sleep(nSecond); SV0h'd(b
} B78e*nNS#2
catch(Exception e) _)?59
{ n6]8W^g
e.printStackTrace (); MYVgi{
} )tW0iFY
} =9AX\2w*H;
soXIPf
//日志 2/m4|
public static void log(String sMsg) hFp\,QSx
{ )UgLs|G~
System.err.println(sMsg); sw^4h`^'
} JcDcYB
1Vy8TV3D
\DC0`
public static void log(int sMsg) :@8N${7`$A
{ 14 Toi
System.err.println(sMsg); Q'qz(G0
} =AIeYUh
} M6o"|\
$vK(Qm
[DzZ:8
/* BL^\"Xh$|
**TestMethod.java |qFCzK9tD/
*/ _^ny(zy(
package NetFox; nqMXE82
qRnD{g|{1
@nOj6b
public class TestMethod { vlS+UFH0
3BzC'nplm
vle`#c.
public TestMethod() ev"f@y9Do
{ ///xx/weblogic60b2_win.exe X&14;lu%p
try{ C_ 4(-OWq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j}fu|-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9H#;i]t&
SiteFileFetch fileFetch = new SiteFileFetch(bean); g/f^|:
fileFetch.start(); R Q2DTQ-$
} "vL,c]D
catch(Exception e){e.printStackTrace ();} C!z7sOu
eN{ewn#0.
{usv*Cm
} \\UOpl
r(6$.zx
a 0+W-#G
public static void main(String[] args) D@ 4sq^|2
{ 3F ]30
new TestMethod(); qb1JE[2F
} e=u?-8
} > t~2
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