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)); ;|oem\dKv
} ,LL=b-Es
for(int i=0;i<nEndPos.length-1;i++) _n4C~
{ xB}B1H%
nEndPos = nStartPos[i+1]; S^~ lQ|D
} 4>]B8ZxH
nEndPos[nEndPos.length-1] = nFileLength; @rr\Jf""z
} hr g'Z5n
} ;Udx|1o
al4X}
kB-<17
//启动子线程 m\K1Ex
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `,FhCT5
for(int i=0;i<nStartPos.length;i++) ''.\DC~K
{ QVD^p;b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z~;@Mo"*f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +@\=v}: F
nStartPos,nEndPos,i); IY|>'}UU#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3[%n@i4H|
fileSplitterFetch.start(); .?r}3Ch
} tCu9 D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D]K?ntS[*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |1/?>=dDm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PxJvE*6^H
nEndPos = " + nFileLength); .y#>mXm>
// fileSplitterFetch[nPos.length-1].start(); SFRYX,0m
Lx3`.F\mG
L$[1+*
//等待子线程结束 f5.Be%
//int count = 0; \%.&$z3wz
//是否结束while循环 *(nu0
boolean breakWhile = false; Bo/i =/7%
~Ecx>f4nX
?lIh&C8]X
while(!bStop) bWMb@zm
{ 4& 9V
write_nPos(); EL9JM}%0v
Utility.sleep(500); r#^uY:T%
breakWhile = true; gE6{R+sp
WhDNt+uk)
uHyc7^X>
for(int i=0;i<nStartPos.length;i++) 6H|&HV(!R
{ !GoHCe[10
if(!fileSplitterFetch.bDownOver) CrX1qyR
{ qkq^oHI
breakWhile = false; >+*lG>!z
break; GUsJF;;V
} L>,xG.oG
} R78lV-};Q
if(breakWhile) ,v(ikPzd
break; e{*z4q1
-M`+hVs?
}M9I]\
//count++; (vbI4&r
//if(count>4) /Fp@j/50
// siteStop(); +<c(;Ucl?
} 7T=:dv
g|)yM^Vqr6
?;p45y~n%
System.err.println("文件下载结束！"); s%)>O{{)
} 4zf(
catch(Exception e){e.printStackTrace ();} n*N`].r#{=
} d?=r:TBU
D(M^%z2N
QeD ;GzG
//获得文件长度 ]U5/!e
public long getFileSize() qApf\o3[0
{ Oa7jLz'i
int nFileLength = -1; uq@_DPA7
try{ HQrx9CXE
URL url = new URL(siteInfoBean.getSSiteURL()); 7]8apei|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (EOYJHZB!
httpConnection.setRequestProperty("User-Agent","NetFox"); Gv6#LcF#
k)S'@>n{u
}zHG]k,j
int responseCode=httpConnection.getResponseCode(); {OW.^UIq^
if(responseCode>=400) BE," lX
{ t8"yAYj
processErrorCode(responseCode); CNyV6jb
return -2; //-2 represent access is error fb|lWEw5h.
} _U%2J4T2
nnMRp7LQ-
((]Sy,rdk
String sHeader; &+8cI^kp
rNX]tp{j
e>$E67h<~
for(int i=1;;i++) FeuqqZ\=&
{ <0H^2ekd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b'G!)n
//Utility.log(in.readLine()); =' #yG(h
sHeader=httpConnection.getHeaderFieldKey(i); <z-+{-?z~
if(sHeader!=null) E%\Ohs7
{ >/DlxYG?
if(sHeader.equals("Content-Length")) IVSd,AR7yY
{ YW^sf,zQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %ZJ;>a#
break; $U}GX'1LZ
} bF? {
} O.OSLezTQ
else &e1(|qax
break; R}\n@X*
} [xg&`x9,.
} lag%}^
catch(IOException e){e.printStackTrace ();} 47 9yG/+\
catch(Exception e){e.printStackTrace ();} g2GHsVS
c=~FXV!
Vw b6QIs
Utility.log(nFileLength); /}RW~ax
$rmfE
Y+_t50S
return nFileLength; W= $, \D+
} r7n-Xe
vrvOPLiQ
wm_o(Z}
//保存下载信息（文件指针位置） #N `Z)}Jm
private void write_nPos() @(LEuYq}
{ 8hm|9
try{ 5j-?Uf
output = new DataOutputStream(new FileOutputStream(tmpFile)); $qh?$a
output.writeInt(nStartPos.length); "A,-/~cBV
for(int i=0;i<nStartPos.length;i++) WY" `wM
{ c~iAjq+c
// output.writeLong(nPos); wdTjJfr
output.writeLong(fileSplitterFetch.nStartPos); Ce_ES.
output.writeLong(fileSplitterFetch.nEndPos); B&c*KaK;~
} D$G:#z*
output.close(); \*6Ld%:h$
} :sXn*k4v
catch(IOException e){e.printStackTrace ();} W\JwEb9Y
catch(Exception e){e.printStackTrace ();} /|2 hW`G
} cSs??i D"q
hQ}B?'>
N?krlR
//读取保存的下载信息（文件指针位置） @F0+t;
private void read_nPos() U<mFwJ C]
{ x6B_5eF
try{ oN7JNMT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y(0";\V
int nCount = input.readInt(); IJV1=/NJW
nStartPos = new long[nCount]; '"14(BvW
nEndPos = new long[nCount]; lq\/E`fc`
for(int i=0;i<nStartPos.length;i++) b)Dzau
{ &Ew{{t;"
nStartPos = input.readLong(); D\i8WU
nEndPos = input.readLong(); ~V<imF
} Id;YIycXe
input.close(); l|p \8=
} ?:XbZ"25pJ
catch(IOException e){e.printStackTrace ();} "OO"Ab{t
catch(Exception e){e.printStackTrace ();} l9Sx'<
} $M 1/74
T`.RP&2/d
or{X{_X7
private void processErrorCode(int nErrorCode) %>Y86>mVz
{ Pn|*(sTl
System.err.println("Error Code : " + nErrorCode); beCTOmC
} ~]&,v|g&
l d4#jV ei
-<Zs7(
//停止文件下载 S8$kxQg
public void siteStop() QvN=<V
{ W_ hckq.
bStop = true; #^~[\8v>
for(int i=0;i<nStartPos.length;i++) N++jI(
fileSplitterFetch.splitterStop(); P(#by{s
7Ta",S@m
8rx"D`{|
} WbW@V_rr
} ME%W,B.|"s
//负责部分文件的抓取 jk'.Gz
**FileSplitterFetch.java :;(zA_-
*/ 251^>x.R
package NetFox; DYKJVn7w
'Bv)UfZ
\E3evU
import java.io.*; !9knFt43
import java.net.*; O>j_xW]V
kLw07&H
WfDpeXdO
public class FileSplitterFetch extends Thread { {Ex*8sU%p%
kt*""&R
_H+|Ic
String sURL; //File URL 5VG[FY6Pl
long nStartPos; //File Snippet Start Position #A '|O\RGP
long nEndPos; //File Snippet End Position CZL:&~l1
int nThreadID; //Thread's ID 5s'oVO*hW
boolean bDownOver = false; //Downing is over {q-<1|xj/J
boolean bStop = false; //Stop identical "Wz#<! .r
FileAccessI fileAccessI = null; //File Access interface . w_oWmD
}+fMYgw
R|Lr@k{6+r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 05cyWg9a
{ [spJ%AhV
this.sURL = sURL; L| uoFG{
this.nStartPos = nStart; ~:\QC
this.nEndPos = nEnd; #gL$~.1
nThreadID = id; |/R)FT#i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W%xg;uzp
} MWxv\o
N5%zbfKM
9j;L-
public void run() ~;*SW[4
{ SXW8p>1Jw
while(nStartPos < nEndPos && !bStop) <[eE5X(
{ oS/cS)N20
N=QeeAI}}m
DFKumw>!
try{ ?!:$Z4G
URL url = new URL(sURL); 9svnB@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m.}Yn,
httpConnection.setRequestProperty("User-Agent","NetFox"); 5D32d1A
String sProperty = "bytes="+nStartPos+"-"; nf7l}^/UE
httpConnection.setRequestProperty("RANGE",sProperty); dDAIfe2y
Utility.log(sProperty); 1UHStR
w,t>M_(N
_rz*7-ks=
InputStream input = httpConnection.getInputStream(); mrzrQ@sN
//logResponseHead(httpConnection); dvAvG.;U
JIl<4 %A
H|1owmbD
byte[] b = new byte[1024]; f"=1_*eH
int nRead; -xc*R%k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~ "^]\3#
{ *[-% .=[7
nStartPos += fileAccessI.write(b,0,nRead); /WlpRf%
//if(nThreadID == 1) )L*6xTa~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b0A*zQA_)
} QeK@++EVc
xMAfa>]{n
a5v}w7vL
Utility.log("Thread " + nThreadID + " is over!"); b#:Pl`n6u
bDownOver = true; nty^De%
//nPos = fileAccessI.write (b,0,nRead); |]dA`e&y
} ^=H. .pr
catch(Exception e){e.printStackTrace ();} Fo=hL
} \BV$p2m5-
} )}-,4Iu%
= h _>OA
8b0!eB#_Ee
//打印回应的头信息 !ys82
public void logResponseHead(HttpURLConnection con) 4xg7oo0iJ
{ rNgFsFQ>.
for(int i=1;;i++) G d".zsn
{ 1^*M*>&d<
String header=con.getHeaderFieldKey(i); z%Xz*uu(|
if(header!=null) VOkEDH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u}eqU%
Utility.log(header+" : "+con.getHeaderField(header)); y5d=r]_S:
else E|(T(4;
break; s&<6{AU(id
} JMMT886
} U4J9bp|
|mSFa8G@
/kl41gx
public void splitterStop() gD"]uj<
{ R. sRH/6
bStop = true; {9tKq--@E9
} 2;Ij~~
2VrO8q(
J33enQd
} 3;wAm/Z:Q
td:GZ %
kEH(\3,l
/* h|=<I)}z
**FileAccess.java X=i^[?C
*//文件访问(定位，写) As$:V<Z
package NetFox; 0w0\TWz*
import java.io.*; *o}LI6_u
[jPUAr}
wA+QUN3#n
public class FileAccessI implements Serializable{ -6URM`y'j
2S~cW./#fX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t% -"h|
RandomAccessFile oSavedFile; %h)6o99{wF
long nPos; <oweLRt
d|^cKLu
uSeRn@
public FileAccessI() throws IOException h]wahExYP
{ ]SqLF!S(=
this("",0); ,]1oG=`3v
} ^sLnKAN
:L~{Q>o
6TN!63{Cz
public FileAccessI(String sName,long nPos) throws IOException 9n#Q1Xq
{ G~SgI>Q
oSavedFile = new RandomAccessFile(sName,"rw"); [^rT: %Z
this.nPos = nPos; f`zH#{u
oSavedFile.seek(nPos); Q.3oDq
} Q&zEa0^rG6
' }G!D
[I4:R_\
public synchronized int write(byte[] b,int nStart,int nLen) L/2{}l>D
{ So&an !
int n = -1; zh5$$*\
try{ J^}w,r*=
oSavedFile.write(b,nStart,nLen); o5!"dxR
n = nLen; Q_ zGs6
} *h+@a
catch(IOException e) Pm2T!0
{ Y<~Nx~w{
e.printStackTrace (); X6+2~'*t
} I%.96V
~hubh!d=
OQ[E-%v1 R
return n; t7A '
} KC+C?]~M
qTbY'V5A
1ga-8&!
} ]:lqbg[J
1`t4wD$/
t`PA85.|d
/* ~i`@
**SiteInfoBean.java u"rK5'
*/ tCT-cs
package NetFox; AJ0qq
[x`trypg
l[KFK%?
public class SiteInfoBean { Y)?dq(
"`b"PQ<x
n5nV461U
private String sSiteURL; //Site's URL G8c 8`~t
private String sFilePath; //Saved File's Path Irk@#,{<
private String sFileName; //Saved File's Name =5NM =K
private int nSplitter; //Count of Splited Downloading File R|7yhsJq,
$ O1w6\}_
x?hdC)#DWI
public SiteInfoBean() bU`Ih# q
{//nSplitter的缺省值为5 Vb${Oy+
//default value of nSplitter is 5 +f{CfWIKs
this("","","",5); ('!{kVLT-
} :}r^sD
q#fj?`k
]dZ8]I<$C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $"P9I-\m
{ x/nlIoT
sSiteURL= sURL; f1cQ*#2~
sFilePath = sPath; %s.hqr,I
sFileName = sName; Ql1HaC/5)-
this.nSplitter = nSpiltter; zzf;3S?
k+X=8()k
=[wVRQ?
} wzX 1!?
("2ukHc
l,FK\
public String getSSiteURL() dXAKk[uf
{ Kjbz\~
return sSiteURL; y`"~zq0D
} //c<p
:D-xa!7
T*,kBJ
public void setSSiteURL(String value) */=5m]
{ a );>
sSiteURL = value; ?klV;+
} [Z2:3*5r.
/*5t@_0fe
t;P%&:"@M
public String getSFilePath() DNsDEU
{ 4"$K66yk@
return sFilePath; >KjyxJ7
} =NyN.^bwT
uzf@49m]m
g8 (zvG;Y
public void setSFilePath(String value) |_&Tu#er3
{ e:9CD-
sFilePath = value; => .EDL.
} a6K1-SR^6)
"=l<%em
P;%4Imq3
public String getSFileName() w(w%~;\kLP
{ d4"KM+EP?
return sFileName; 3kxI'0&T
} GarPnb
kyQUaFG
SvUC8y
public void setSFileName(String value) Am~NBQ7
{ xrbDqA.b
sFileName = value; |*4)G6J@n
} Pb0+z=L
neQ2k=ao
pWo`iM& F
public int getNSplitter() Wsb=SM7;
{ ei 1(A
return nSplitter; ()=u#y
} 0sjw`<ic
zV)Ob0M7U
m?;aTSa
public void setNSplitter(int nCount) po~l8p>
{ A1xY8?#?~c
nSplitter = nCount; )A]E:]2
} 8Z;wF
} h.Cr;w,2R
*uYnu|UQH
q2VQS1R`8
/* 'jp nQcwxx
**Utility.java w$J0/eX{A
*/ 8fpaY{]
package NetFox; 27b7~!
S5:`fo^5
{e,m<mAi
public class Utility { hw`+,_ g
&(!Sy?tNe
x{u7#s1|/
public Utility() pm<zw-
{ {r2-^QHF
YQ>P{I%J
~8'4/wh+8
} K~nk:}3Ui
7&G[mOx0
//线程睡眠 bK `'zi
public static void sleep(int nSecond) ]a|3"DP5
{ V}732?Jy
try{ G!~[+B
Thread.sleep(nSecond); <wwcPe}
} 3 wVN:g7
catch(Exception e) kq6K<e4jO
{ 0dhJ# [Y
e.printStackTrace (); 9NwA5TP9_
} ZVotIQ/Q'
} B 95}_q
Tfc5R;Rw
//日志 {.9phW4Vr?
public static void log(String sMsg) jRXpEiM
{ )I<p<HQD
System.err.println(sMsg); J&~nD(&TY
} eWO^n>Y
[T', ZLR|
ocwRU0+j
public static void log(int sMsg) R4,j
{ ^.Y"<oZSS
System.err.println(sMsg); >LxYP7M
} }S6Sz&)
} 2Mx9Kd'a r
Z(AI]wk3<
11}fPWK
/* .?b2Bd!MC
**TestMethod.java .fxI)
*/ CQfrAk4mu
package NetFox; ?4=8z8((!
6L~@jg~0A[
\RZFq<6>
public class TestMethod { WSfla~-'F
^=Rqa \;
.)^@[yrkz
public TestMethod() 0A[p3xE\
{ ///xx/weblogic60b2_win.exe &)L2a)
try{ s)%RmsdL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 07-S%L7Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uh}n'Xd#{}
SiteFileFetch fileFetch = new SiteFileFetch(bean); P8.tl"q
fileFetch.start(); iZ+\vO?|
} "|pNS)
catch(Exception e){e.printStackTrace ();} UM%[UyYQ
cOra`7L`
a#W:SgE?Y
} wL,b.]
}*l V
fAWjk&9
public static void main(String[] args) ,YFuMek
{ NUBzmnA>8
new TestMethod(); 0`/PEK{
} vrXmzq
} ?iG}Qj@5
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