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)); G_n~1?
} yM*<BV
for(int i=0;i<nEndPos.length-1;i++) $iAd)2LT
{ _^u^@.Q'i<
nEndPos = nStartPos[i+1]; a'A'%+2
} E,:E u<
nEndPos[nEndPos.length-1] = nFileLength; /kK:{
} \I`g[nT|
} e't1.%w
!mRDzr7
3k?|-js
//启动子线程 S.A|(?x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !V;glx[
for(int i=0;i<nStartPos.length;i++) &IgH]?t
{ cu$i8$?t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $79-)4;z4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n!t][d/g+
nStartPos,nEndPos,i); .</.(7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tR% &.,2
fileSplitterFetch.start(); B< BS>(Nr>
} 14;lB.$p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wc-8j2M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XP!7@:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pi:=0,"XOp
nEndPos = " + nFileLength); i5^U1K\M
// fileSplitterFetch[nPos.length-1].start(); W8{zV_TBm
|F^h>^ x
%oEvp{I
//等待子线程结束 x$\w^h\F
//int count = 0; /0I=?+QSo
//是否结束while循环 Di8;Tq
boolean breakWhile = false; \mp5G&+/Q
%G>V .d
8NzXe 7
while(!bStop) TZ+2S93c
{ `h|>;u
write_nPos(); >n^[-SWJCT
Utility.sleep(500); sOLR*=F{
breakWhile = true; &24z`ZS[w6
@s/0 .7
Kw^tvRt'*
for(int i=0;i<nStartPos.length;i++) [?Ub =sp
{ i@XFnt
if(!fileSplitterFetch.bDownOver) CHRO9
{ oc3}L^aD
breakWhile = false; b5Pakz=jNM
break; 9F"Q2^l'
} `OmYz{*r
} L=WB'*N
if(breakWhile) 9K`uGu
break; !~~j&+hK\
gC qQ~lWZ
M~&X?/8
//count++; nzK"eNDN.
//if(count>4) <<[hZ$.
// siteStop(); 'U'#_mYG
} *=ymK*
r@m2foaO
2r|!:^'?W
System.err.println("文件下载结束！"); wk"zpI7L
} "G`8>1tO_
catch(Exception e){e.printStackTrace ();} Z w&_Wt
} y3vm+tJc{
^9C9[$Q
{<3>^ o|"
//获得文件长度 ;Jrk#7
public long getFileSize() Yi+~}YP.E(
{ kGX;x}q
int nFileLength = -1; ]\t+zF>&Y
try{ HGjGV]N5
URL url = new URL(siteInfoBean.getSSiteURL()); :'LG%E:b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =wy3h0k^
httpConnection.setRequestProperty("User-Agent","NetFox"); ^."HD(
IN%04~=H
`e!hT@Xxa
int responseCode=httpConnection.getResponseCode(); w+0Ch1$
if(responseCode>=400) /o_h'l|PS
{ )4P5i b
processErrorCode(responseCode); Qe )#'$T
return -2; //-2 represent access is error axW4cS ?
} ].eY]o}=
)tV^)n[w
BsX# ~
String sHeader; \!tS|h
Lx"a#rZ
mTW@E#)n
for(int i=1;;i++) `1[GY){?)
{ %g>{m2o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PNbs7f
//Utility.log(in.readLine()); !F|iL
sHeader=httpConnection.getHeaderFieldKey(i); k5@_8Rc
if(sHeader!=null) hoQ?8}r:
{ #`0iN+qh
if(sHeader.equals("Content-Length")) -^JGa{9*
{ |e@Bi#M[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Um$a9S8b&
break; UT9=S21
} HGgw<Os-k
} \O7?!i
else Tcglt>tj"
break; Ht'jm(
} '\2lWR]ndd
} Z)U#5|sf
catch(IOException e){e.printStackTrace ();} ;')T}wuq
catch(Exception e){e.printStackTrace ();} _z!0ab
'd"\h#
X&<#3n
Utility.log(nFileLength); -^(NIl'
L^`oJ9k!
.F~EQ %
return nFileLength; cg,_nG]i
} }<wj~f([
+(3PY e\
|7CH
//保存下载信息（文件指针位置） "iof -b=ys
private void write_nPos() 8bX\^&N
{ \?} {wh8
try{ A*h)p@3t<
output = new DataOutputStream(new FileOutputStream(tmpFile)); [^gSWU
output.writeInt(nStartPos.length); '7F`qL\/#(
for(int i=0;i<nStartPos.length;i++) H\kqmPl&
{ ^/Hj^4~_U
// output.writeLong(nPos); k*4?fr
output.writeLong(fileSplitterFetch.nStartPos); m,u? ^W
output.writeLong(fileSplitterFetch.nEndPos); >oc7=F<8lS
} R$cO`L*s
output.close(); Pc]c8~
} Ej1 [ry
catch(IOException e){e.printStackTrace ();} VmTk4?V4
catch(Exception e){e.printStackTrace ();} b)u9#%Q
} d]e`t"Aj
r)mm8MI!Z
)N-+,Ms
//读取保存的下载信息（文件指针位置） UY**3MK
private void read_nPos() @ %z5]w
{ l1odkNf|
try{ n20H{TA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IBVP4&}x$
int nCount = input.readInt(); WII_s|YSt%
nStartPos = new long[nCount]; 0EXAdRR
nEndPos = new long[nCount]; kmW!0hm;e
for(int i=0;i<nStartPos.length;i++) lb1(1|#
{ \Mlj 7.u]
nStartPos = input.readLong(); U gB
nEndPos = input.readLong(); e7L;{+XI
} LFSOHJj
input.close(); su=.4JcK
} xuelo0h,
catch(IOException e){e.printStackTrace ();} "0L@cOyG
catch(Exception e){e.printStackTrace ();} ?NI)3-l
} %!rsu-W:Y
,XP9NHE
i=2+1;K
private void processErrorCode(int nErrorCode) UsQv!Cwu^
{ NUL~zb
System.err.println("Error Code : " + nErrorCode); #G#gB
} p,D/ Pb8
yB.6U56
c2"eq2'BS
//停止文件下载 kXX RMR
public void siteStop() v%aD:%wlY@
{ 5<w0*~Zd~
bStop = true; qrX6FI
for(int i=0;i<nStartPos.length;i++) o7 !@WOeZ3
fileSplitterFetch.splitterStop(); '~ ]b;nA
kd\yHI9A
Mdwh-Cis/
} !s)2H/KM8
} _k+Bj.L
//负责部分文件的抓取 *rEW@06^\
**FileSplitterFetch.java iCx'`^HnP
*/ g1J]z<&
package NetFox; f\(Kou$
db%`-UST
P6=|C;[
import java.io.*; # |UrHK;
import java.net.*; ;U`HvIch
5WZLB =
103Ik6.o
public class FileSplitterFetch extends Thread { _X.M,id
&P{%C5?{
8'cDK[L
String sURL; //File URL 3YT _GW{
long nStartPos; //File Snippet Start Position 'ZDa*9nkF
long nEndPos; //File Snippet End Position <I|ryPU9{X
int nThreadID; //Thread's ID jA]xpf6}
boolean bDownOver = false; //Downing is over v5$zz w
boolean bStop = false; //Stop identical -=qmYf
FileAccessI fileAccessI = null; //File Access interface fCVSVn"o
Yp ? 2<
|R[m&uOib
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YT:5J%"
{ cL WM]\Y
this.sURL = sURL; 9Pb0Olh
this.nStartPos = nStart; 0^[$0]Mt[
this.nEndPos = nEnd; fg1 zT~
nThreadID = id; =q"3a9pb7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ahebr{u
} X>wQYIi
JqZ%*^O
Y.C*|p#
public void run() QnGJ4F
{ }M~AkJL
while(nStartPos < nEndPos && !bStop) ]jYl:41yI
{ dvj`%?=
,,iQG' *
"M*\,IH
try{ @LmUCP~
URL url = new URL(sURL); E|fPI u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $ `ho+
httpConnection.setRequestProperty("User-Agent","NetFox"); <St`"H
String sProperty = "bytes="+nStartPos+"-"; (HJ60Hj
httpConnection.setRequestProperty("RANGE",sProperty); Yp;x
Utility.log(sProperty); Sn+Yi
7vWB=r>5@
~gAx
InputStream input = httpConnection.getInputStream(); HYY|)Wo
//logResponseHead(httpConnection); [p(C:rH
;}PL/L$L6;
N,1wfOE
byte[] b = new byte[1024]; TUUBC%
int nRead; 6$Dbeb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #QB`'2)vw
{ Ar$LA"vu4
nStartPos += fileAccessI.write(b,0,nRead); }$UFc1He\J
//if(nThreadID == 1) I'j?T.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w7W-=\Hvh
} #nd,cn
_8`|KY
8_LDS
Utility.log("Thread " + nThreadID + " is over!"); r#j*vO '
bDownOver = true; &vn9l#\(
//nPos = fileAccessI.write (b,0,nRead); RU'J!-w{
} HvngjP{>
catch(Exception e){e.printStackTrace ();} _1Eyqh`oh
} ["7}u^z@<+
} Cm&itG
Tv KX8m"
aG ,uF
//打印回应的头信息 &V;a:
public void logResponseHead(HttpURLConnection con) .6hH}BM
{ I F@M
for(int i=1;;i++) Nf~<xK
{ -Z@p
String header=con.getHeaderFieldKey(i); O| 2Q- @D
if(header!=null) _Dv^~e1c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ppYz~ {"r
Utility.log(header+" : "+con.getHeaderField(header)); r3-3*_
else i>~?XVU
break; D'&LwU,o
} :z:Blp>nK/
} Mc6y'w
96BMJE'
G1l(
public void splitterStop() GB=q}@&8p
{ e'`oisJU?q
bStop = true; N4:'X6u;
} : ?V;
?-f>zx8O
Cr` 0C
} Yc$|"to
)0Lq>6j9
2Ar<(v$
/* zaZnL7ZJX
**FileAccess.java ZUu^==a
*//文件访问(定位，写) W< n`[
package NetFox; 9NT;^K^I
import java.io.*; i_MI!o
gr;M
(pmo[2kg
public class FileAccessI implements Serializable{ EDo (
|h7v}Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H07j&
RandomAccessFile oSavedFile; |}`5<a!6U
long nPos; (TE2t7ab|M
VC.?]'OqD
qEAF!iB]L
public FileAccessI() throws IOException r>Ln*R,9D
{ I?>#neHc6
this("",0); <%z/6I Af|
} B4}XK=)
Y[!a82MTzn
]Q3Gj@6
public FileAccessI(String sName,long nPos) throws IOException 8VZ-`?p
{ zCHr
oSavedFile = new RandomAccessFile(sName,"rw"); x3Ud0[(
this.nPos = nPos; xeI{i{8
oSavedFile.seek(nPos); "YL-!P
} :3B\,inJ
$c}0L0
}$-VI\96
public synchronized int write(byte[] b,int nStart,int nLen) a%dx\&K
{ pd#/;LT
int n = -1; b5DrwX{Ff
try{ L,6Y=?
oSavedFile.write(b,nStart,nLen); v\Ljm,+
n = nLen; |=LkV"_v
} FT~^$)8=
catch(IOException e) 4i,SiFKB
{ Bu1z$#AC
e.printStackTrace (); #lF<="y%X
} c #kV+n<
mV,R0olF
^aXBt
return n; "b 0cj
} aJ8pJ{,P
rg,63r
vNC0M:p,
} ]D%k)<YK
N-gRfra+8L
H#inr^Xa
/* E: GJ$I
**SiteInfoBean.java $J6.a!5IE
*/ LzRiiP^q
package NetFox; \#aVu^`eX
?^~"x.<nr
yUO|3ONT
public class SiteInfoBean { {ZXC%(u
PoJ$%_a}
L2'd sOn
private String sSiteURL; //Site's URL :2E1aVo4b
private String sFilePath; //Saved File's Path j&A3s{S4A
private String sFileName; //Saved File's Name opMUt,4
private int nSplitter; //Count of Splited Downloading File KIo}Gd&
ZRB 0OH
Yys~p2
public SiteInfoBean() PQ}%}S7:
{//nSplitter的缺省值为5 |lxy< C4V
//default value of nSplitter is 5 hZ<btN.y5
this("","","",5); cA? x(
} |L;psK
xV#a(>-4
Hc]1mM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rf->mk{
{ f_ztnRw
sSiteURL= sURL; /y)"j#-eW
sFilePath = sPath; |A0$XU{
sFileName = sName; v9U(sEDq
this.nSplitter = nSpiltter; 6;cY!
Da[C'm=
N@6OQ:,[F
} Z=@)
u!o]Co>
NRisr
public String getSSiteURL() X5Y `(/V
{ e({fY.)SGo
return sSiteURL; S2E HmE&
} PuCDsojclh
4|N\Q=,
o^Ysp&#p
public void setSSiteURL(String value) vQ"s
{ `8;,&<U'`
sSiteURL = value; hF"g91P
} QO{=Wi-
JA(fam~{
EWIc|b:
public String getSFilePath() 3]<re{)J9O
{ *frJ^ Ws{
return sFilePath; S9R]Zl7{-
} k0_$M{@Y
qQOD
_1<'"u#6w
public void setSFilePath(String value) tRnW%F5
{ {Y91vXTz7
sFilePath = value; 6@q[tN7_^
} oL'1Gm@X?
.3<IOtD=
Jh4&Qh|t
public String getSFileName() 3;MjO*-
{ ZuvPDW%
return sFileName; V.ji _vX
} ] 5v4^mk
qmA2bw]
oL Vtu5
public void setSFileName(String value) qzA]2'~Q
{ 0sDwTb"
sFileName = value; BwJ^_:(p~
} b/B`&CIA0"
Y^2Qxo3"3
u:$x6/t
public int getNSplitter() j-YJ."
{ a4(?]ND~6
return nSplitter; 6lmiMU&V
} q^1aPz
$tCcjBK\
{^2W>^
public void setNSplitter(int nCount) f{Fe+iPc
{ 'B (eMnLg
nSplitter = nCount; LuP?$~z
} hiRR+`L%
} cZr G:\A
Vp$wHB&
a-5HIY5
/* "f|(@a
**Utility.java pAil]f6
*/ sQ}%7BMK
package NetFox; <s/<b*T ^
d)0LVa(
(+UmUx=
public class Utility { LR3`=Z9
~#"7,rQp
)ojx_3j8
public Utility() Nxb\[
{ _t|G@D{
+Cf0Y2*@hM
YxEbg(Y
} qA/#IUi)1
mT6q}``vtG
//线程睡眠 /e|[SITe
public static void sleep(int nSecond) 8Y\OCwO
{ HX3D*2v":
try{ [Iw>|q<e
Thread.sleep(nSecond); IAP/G5'Q
} C[xJU6z
catch(Exception e) 1t~FW-:
{ Y .
e.printStackTrace (); dXiE.Si
} 1xO!w+J#
} )d}H>Qx=
ut4r~~Ar
//日志 v._Egk0
public static void log(String sMsg) %9T~8L @.
{ Dc.n-ipv$
System.err.println(sMsg); M!Z*QY."P
} hIVI\U,
3cOY0Z#T
jVad)2D
public static void log(int sMsg) *%X6F~h(u
{ vZb|!#I
System.err.println(sMsg); -c+[6A>j
} >-5td=:Z
} .!yWF?T8
1mHwYT+
ofMu3$Q
/* ZD5I5
**TestMethod.java uw Kh
*/ VY/|WD~"CW
package NetFox; j-J(C[[9
48tcgFg[
M*5,O
public class TestMethod { uW}Hvj;0a*
URYZV8=B~
q.=^iz&m
public TestMethod() e9CP802#2
{ ///xx/weblogic60b2_win.exe +`;+RDKY*
try{ 0A#*4ap
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N[qA2+e$Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _1>SG2h{fV
SiteFileFetch fileFetch = new SiteFileFetch(bean); fav5e'[$
fileFetch.start(); R=-+YBw7/
} *8$>Whr
catch(Exception e){e.printStackTrace ();} X"h%tsuw
-7>^ rR V
`"a? a5]k
} 8P,l>HA
WD15pq l
iH-bo@
public static void main(String[] args) 2E$^_YT C
{ EXA^!/)
new TestMethod(); Ci~f#{
} tm(v~L%$>]
} JY{X,?s
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