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)); duk:: |{F
} KGoHn6jM
for(int i=0;i<nEndPos.length-1;i++) I_h{n{,sr
{ 81<0B@E
nEndPos = nStartPos[i+1]; +|=5zWI/
} 7yK1Q_XY>
nEndPos[nEndPos.length-1] = nFileLength; 8${Yu
} `Ufv,_n
} Vdz(\-}ao
#RA3 T[A
qTl/bFD
//启动子线程 U\\nSU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0{ ;[k
for(int i=0;i<nStartPos.length;i++) +\O[)\
{ q"Z!}^{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6Y[|xu:N8Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WDdp(<
nStartPos,nEndPos,i); $=-Q]ld&]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ']]&<B}mz
fileSplitterFetch.start(); GXE6=BO
} @\UoZv(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qm&Z_6Pw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4/Bn9F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %g<J"/
nEndPos = " + nFileLength); _%$(D"^j
// fileSplitterFetch[nPos.length-1].start(); Y[yw8a
/-W-MP=Wd
BLvI[b|3gn
//等待子线程结束 r\-25F<e5
//int count = 0; hIr$^%
//是否结束while循环 yw(E}
boolean breakWhile = false; k v}<u
+.b@rU6H
)5Bkm{v3
while(!bStop) a}w%k
{ _2,eS[wP
write_nPos(); <?I s~[2
Utility.sleep(500); H~P"uYKIZ
breakWhile = true; pM i w9}
C,!}WB@VME
E(&GZ QE
for(int i=0;i<nStartPos.length;i++) G2,r%|7ta
{ ) -C9W7?I
if(!fileSplitterFetch.bDownOver) XI*_ti
{ DB>Y#2j4h
breakWhile = false; {&Bpf K;`)
break; @-ma_0cZQ
} /@.c 59r
} !^|%Z
if(breakWhile) VnJ-nfA
break; ab=s+[r1
hR$lX8
%YaUc{.%
//count++; ^3-Wxn9&
//if(count>4) ;^,2 QsM
// siteStop(); L8~nx}UP5
} O&:0mpRZ
7Pc0|Z/
w$5N6
System.err.println("文件下载结束！"); Vd{h|=J
} #NVqS5
catch(Exception e){e.printStackTrace ();} ] _/d
} YW}1iT/H
Qjj:r~l
Qn7l-:`?
//获得文件长度 |m%M$^sZ}
public long getFileSize() &E{5k{Y
{ ')9%eBaeK
int nFileLength = -1; @x@w<e%
try{ ItTIU
URL url = new URL(siteInfoBean.getSSiteURL()); JL9d&7-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J9LS6~ 7
httpConnection.setRequestProperty("User-Agent","NetFox"); I@=h|GM
X'&$wQ6,K
,qRSB>5c
int responseCode=httpConnection.getResponseCode(); 3"gifE
if(responseCode>=400) RTSR-<{z
{ {}3kla{
processErrorCode(responseCode); bmAgB}Ior
return -2; //-2 represent access is error sK:,c5^
} {I|k@
xX'Uq_Jv
ndm19M8Y|
String sHeader; gKZ{O
|<.b:e\4
|7Q8WjCQ{m
for(int i=1;;i++) R0<ka[+
{ n;"4`6L~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J{mP5<8>b
//Utility.log(in.readLine()); 4:}`X
sHeader=httpConnection.getHeaderFieldKey(i); QD:0iD?
if(sHeader!=null) 0<L@f=i
{ lO9{S=N
if(sHeader.equals("Content-Length")) %f;(
{ ~MY(6P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;f-|rC_"
break; W4CI=94
} Z"gllpDr$
} oQDOwM,
else co3H=#2a
break; \i-jME(sN
} =tcPYYD
} *eXO?6f%s^
catch(IOException e){e.printStackTrace ();} ^c]Sl
catch(Exception e){e.printStackTrace ();} 2LYd # !i
ZZC= 7FB
dW7dMx
Utility.log(nFileLength); q rbF@{
}bznx[4?I
fC3IxlG
return nFileLength; ud:?~?j&w
} K23_1-mbe
~rCnST
cM4?Ggn
//保存下载信息（文件指针位置） !E_uQ?/w]Z
private void write_nPos() savz>E&
{ ID+'$u&
try{ g}^/8rW
output = new DataOutputStream(new FileOutputStream(tmpFile)); YY!(/<VI
output.writeInt(nStartPos.length); zFi+6I$
for(int i=0;i<nStartPos.length;i++) A?}OOjA
{ 0h shHv-
// output.writeLong(nPos); 0]oQ08
output.writeLong(fileSplitterFetch.nStartPos); J-PzIFWd
output.writeLong(fileSplitterFetch.nEndPos); ^y6Pkb P
} 0K3FH&.%
output.close(); 6 qKIz{;
} e3>Re![_.
catch(IOException e){e.printStackTrace ();} 8)POEY4
catch(Exception e){e.printStackTrace ();} )Elr8XLw
} }2c}y7B,_
Br~%S?4"o
jZ D\u%
//读取保存的下载信息（文件指针位置） vWkKNB
private void read_nPos() @B9|{[P
{ 4\OELU
try{ C-Fp)Zs{0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ee|+uQ981>
int nCount = input.readInt(); W=EO=}l#
nStartPos = new long[nCount]; f[}SS]d:E
nEndPos = new long[nCount]; <Ab:yD`K!
for(int i=0;i<nStartPos.length;i++) (Z"Xp{u
{ ~$\j$/A8/
nStartPos = input.readLong(); @J<B^_+Se
nEndPos = input.readLong(); #8z\i2I
} d}o1 j
input.close(); `f'q/
} fd,~Yj$R?
catch(IOException e){e.printStackTrace ();} oM7^h3R
catch(Exception e){e.printStackTrace ();} lwg.'<
} ;W+-x]O
Z],"<[E
_5m }g!
private void processErrorCode(int nErrorCode) b/K&8C,c
{ ai`:HhE
System.err.println("Error Code : " + nErrorCode); =!CuCV7$1O
} yX~[yH+Pn
m~U{ V9;*
F>b6fUtR
//停止文件下载 (&*F`\
public void siteStop() '9/kDkt!
{ blN1Q%m6
bStop = true; Qx,G3m[}
for(int i=0;i<nStartPos.length;i++) .4Ny4CMHZ
fileSplitterFetch.splitterStop(); bp$jD
}[DAk~
z>0"T2W y
} a,4g`?
} V]O :;(W_
//负责部分文件的抓取 Ur-^X(nL
**FileSplitterFetch.java _N:h&uw
*/ u=l(W(9=
package NetFox; .)3 2WD%
eLYFd,?9
YQ)m?=+J
import java.io.*; OWjZ)f/
import java.net.*; 8 KkpXaz
`?@7 KEl>
\;6F-0
public class FileSplitterFetch extends Thread { &rd(q'Vi
YiCDV(prT
$ B9=v
String sURL; //File URL =@w:
long nStartPos; //File Snippet Start Position xKr,XZu
long nEndPos; //File Snippet End Position `SwnKg
int nThreadID; //Thread's ID JgB# EoF
boolean bDownOver = false; //Downing is over heKI<[8l
boolean bStop = false; //Stop identical 2$o[
FileAccessI fileAccessI = null; //File Access interface 0/ Ht;(
b tu:@s8ci
(Lo2fY5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hjG1fgEj
{ ,![=_d
this.sURL = sURL; 7asq]Y}<
this.nStartPos = nStart; XJzXxhk2
this.nEndPos = nEnd; ".)_kt[
nThreadID = id; %yMzgk[u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `-H:j:U{
} Ax0,7,8y
h0 Sf=[>z
W =zG
public void run() ??m7xH5u1
{ 4PWr;&
while(nStartPos < nEndPos && !bStop) S2R[vB4).
{ <n\.S
_6m3$k_[MJ
rxK0<pWJhx
try{ RF)B4D-W
URL url = new URL(sURL); QC4T=E]`j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *jK))|%
httpConnection.setRequestProperty("User-Agent","NetFox"); i-?zwVmn
String sProperty = "bytes="+nStartPos+"-"; @;6}xO2
httpConnection.setRequestProperty("RANGE",sProperty); y2R=%EFh6
Utility.log(sProperty); j1F+,
%-l:_A
|&Pl4P
InputStream input = httpConnection.getInputStream(); m=MT`-:
//logResponseHead(httpConnection); 0'hxw3#
OkZ!ZS h
psC7IE<v
byte[] b = new byte[1024]; doc
int nRead; aHC;p=RQ\A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .e"Qv*[^
{ <dL04F
nStartPos += fileAccessI.write(b,0,nRead); Y/0O9}hf
//if(nThreadID == 1) .dCP8|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u =kSs
} 2]9<%-=S
U_- K6:tr
kkBU<L2
Utility.log("Thread " + nThreadID + " is over!"); l,u{:JC
bDownOver = true; v$G*TR<2
//nPos = fileAccessI.write (b,0,nRead); cf'}*$[S
} C/waH[Yzan
catch(Exception e){e.printStackTrace ();} UWp8I)p!\O
} j#,M@CE
} p^rX.?X
~5uNw*H
6wB>-/'Y
//打印回应的头信息 0NtsFPO
public void logResponseHead(HttpURLConnection con) _-\s[p5
{ ZPsY0IzLo
for(int i=1;;i++) ?0NSjK5ma
{ Ro]IE|Fv
String header=con.getHeaderFieldKey(i); %"Q!5qH&
if(header!=null) <88}+j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eH
Utility.log(header+" : "+con.getHeaderField(header)); T(UYlLe
else mzxvfXSF
break; 2U'JzE^Do
} |/^aLj^u
} 1vs>2` DLa
^Cn]+0G#C8
ff1B)e
public void splitterStop() HoE.//b
{ R9/xC7l@
bStop = true; K}`p_)(
} b*F~%K^i$
~|{)h^]@
Vfm #UvA
} Jf<yTAm
"!Oh#Vf
DUKmwKM"k
/* yr9A0F0
**FileAccess.java |C6(0fgWd
*//文件访问(定位，写) ICbdKgLz
package NetFox; Zmbz-##HQ
import java.io.*; qV8\/7'A0a
NE2sD
jjwMvf.R
public class FileAccessI implements Serializable{ ]a!; `m$
T:%wX9W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PnIvk]"Ab
RandomAccessFile oSavedFile; #D/ }u./
long nPos; y?z_^ppj
gVA}?t;
tD7C7m
public FileAccessI() throws IOException 8^/Ek<Qb|
{ O;BMwg_7
this("",0); B Ff.Rd95
} h"1"h.
*!]Epb
199hQxib:
public FileAccessI(String sName,long nPos) throws IOException _2X6bIE
{ 8wpwJs&V
oSavedFile = new RandomAccessFile(sName,"rw"); renmz,dJ,
this.nPos = nPos; .cT$h?+jyl
oSavedFile.seek(nPos); m)|.:sj
} ZYR,8y
HvgK_'
zHoO?tGf
public synchronized int write(byte[] b,int nStart,int nLen) q8xc70: R
{ yCkW2p]s,K
int n = -1; %{~mk[d3
try{ -?w v}o
oSavedFile.write(b,nStart,nLen); %Di7u- x
n = nLen; ds$\vSd
} ssX6kgq_(
catch(IOException e) @)Hbgkdi
{ zGL<m0C
e.printStackTrace (); 2mG&@E
} hXQg=Sj
?^48Zq6wM
N7$DRG/<b
return n; Z_V&IQo-7
} w[YkTv
v`+n`DT
_2gT1B
} jU4)zN/`r
Q$.V:#
GkGC4*n
/* "Eok;io
**SiteInfoBean.java "l[V%f E
*/ COan)<Ku
package NetFox; nL+YL
W:{PBb"x8
1_j<%1{sZ
public class SiteInfoBean { Tu=eQS|'
d%_78nOh"
t=W$'*P0}
private String sSiteURL; //Site's URL Ca5Sc, no
private String sFilePath; //Saved File's Path kJ#[UCqzM
private String sFileName; //Saved File's Name ^{fi^lL=
private int nSplitter; //Count of Splited Downloading File 4-d99|mv
zN)|g
dW{o+9nw
public SiteInfoBean() Xs%R]KOwt
{//nSplitter的缺省值为5 #}t1
//default value of nSplitter is 5 (J^Lqh_
this("","","",5); <^*+8{*
} +6#%P
OHtgn
}W@#S_-e8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,Og[[0g
{ J]|6l/i
sSiteURL= sURL; K.#,O+-Kg`
sFilePath = sPath; 1fO2)$Y
sFileName = sName; `Dz]z_
this.nSplitter = nSpiltter; mHI4wS>()+
D?\"
@\6nXf
} %7C%`)T]
nv_m!JG7
STXqq[+Rf
public String getSSiteURL() gf3u0' $
{ <(#xOe
return sSiteURL; `b^#quz
} oA!5dpNhU
- 5o<Q'(
k}I5x1>&
public void setSSiteURL(String value) C>JekPeM
{ 7}#*3*]
sSiteURL = value; y?*[}S
} $/<"Si&(
i)@U.-*5m
<@U.
public String getSFilePath() \N`fWh8&
{ MAwC\7n+X
return sFilePath; (^tr}?C
} >Bh)7>`3c
+ 4V1>e+
=qV4Sje|q
public void setSFilePath(String value) Wk\mgGn+
{ `Ct'/h{
sFilePath = value; ;<bj{#mMv
} "o^bN 9=
nl)_`8=
"q9~C
public String getSFileName() WIEx '{
{ a%MzNH
return sFileName; >}dTO/
} ]HJ{dcF
vDK:v$g
;Ch+X$m9
public void setSFileName(String value) 0$xK
{ B91S h`
sFileName = value; Pp1zW3+Q
} 1EC-e|M.
`uIx/.L
pPiYPfs
public int getNSplitter() TZ&4
{ n=<NFkeX
return nSplitter; |dl0B26x
} "t(1tWO1o
!F0rd9
+ AcKB82
public void setNSplitter(int nCount) ?o(ZTlT
{ Aj8l%'h[
nSplitter = nCount; njy~
} };|!Lhl+
} *<`7|BH3
TRs[~K)n
LPq*ZZK
/* ?r -\%_J_(
**Utility.java `DgaO-Dg3
*/ #Acon7Rp
package NetFox; (TT3(|v
:DOr!PNA
o9KyAP$2
public class Utility { bc3|;O
;=5@h!@R
Qa,NGP.
public Utility() itqQ)\W
{ 90
1KeJd&e
egZyng pB
} NqiB8hZ~
JwN}Jm
//线程睡眠 #d}0}7ue
public static void sleep(int nSecond) 4o1Q7
{ :0 W6uFNOU
try{ tx^92R2/
Thread.sleep(nSecond); jgk{'_ j
} `FZ(#GDF
catch(Exception e) K)<Wm,tON
{ b\SXZN)Be
e.printStackTrace (); {c v;w
} 6V'wQqJ
} /M0l p
3[MdUj1y[
//日志 :`:xP
public static void log(String sMsg) RpHpMtvNo/
{ <MPeh&_3#
System.err.println(sMsg); :.C+?$iuX
} ,|e}Y [
Zij"/gx\
Pk$}%;@v
public static void log(int sMsg) kVV\*"9y
{ fC=fJZU7$
System.err.println(sMsg); <T(s\N5B=
} =}~NRmmF
} I["F+kt^^
[:AB$l*
5Z* b(R
/* |$YyjYK
**TestMethod.java BhqhyX\D&y
*/ \w{@u)h
package NetFox; xL9:4'I
AyE%0KmraK
pp/#Am
public class TestMethod { J)-T:.i|0
?F!EB4E\y}
^dFhg_GhF
public TestMethod() s9uL<$,'
{ ///xx/weblogic60b2_win.exe E"Zb};}
try{ }*?yHJ3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Lf5%M|o.)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @)9REA(U
SiteFileFetch fileFetch = new SiteFileFetch(bean); \9046An
fileFetch.start(); Ya~ "R#Uy
} 99J+$A1
catch(Exception e){e.printStackTrace ();} PPUEkvH W
q $t&|{
mG0L !5
} uK$=3[;U/!
dVvZu% DFp
9OPK4-
public static void main(String[] args) v2IEJ
{ *y)4D[ z-
new TestMethod(); #0}Ok98P
} )J;ny!^2
} 6a7vlo
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