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)); $g9**b@
} oPf)be| #
for(int i=0;i<nEndPos.length-1;i++) KL,/2(
{ _*M42<wcO
nEndPos = nStartPos[i+1]; g`^X#-!(
} bBcp9C)iY
nEndPos[nEndPos.length-1] = nFileLength; &C<yfRDu
} jhgX{xc
} Fh|#u:n
SymwAS+
R7jmv n
//启动子线程 >r@.F%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bh`N[\r
for(int i=0;i<nStartPos.length;i++) +avMX&%
{ YUU-D(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G6P)C##ibn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E(pF:po
nStartPos,nEndPos,i); {PU!=IkTS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'wasZ b<^
fileSplitterFetch.start(); UB`ToE|Ii
} m><w0k?t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N7r_77%m0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `$LWmm#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6DIZ@oi
nEndPos = " + nFileLength); ~5 N)f UI\
// fileSplitterFetch[nPos.length-1].start(); -/C)l)V}
O43YY2
$q?$]k|M`
//等待子线程结束 Ox!U8g8c
//int count = 0; lH^^77"4Qo
//是否结束while循环 %.v{N6
boolean breakWhile = false; DhLqhME53
sAn0bX
w>fdQ!RdP
while(!bStop) ^$>XW\yCs
{ ~[o4a'
write_nPos(); Qp,DL@mp>8
Utility.sleep(500); `N//A}9
breakWhile = true; ]Y>h3T~
pL=d% m.W
mMx;yZ
for(int i=0;i<nStartPos.length;i++) !rDdd%Z
{ w.\w1:d
if(!fileSplitterFetch.bDownOver) [S]S^ej*8
{ tY${M^^<J
breakWhile = false; vr^~yEr
break; qLL,F
} [H\:pP8t
} 54;J8XT7
if(breakWhile) 0kQPJWF
break; jxaD&4Fs8
>KLtY|o)
AUVgPXOwd
//count++; b !@Sn/
//if(count>4) qW:)!z3\
// siteStop(); G|w=ez
} , ^F)L|
GDhE[of
4D%9Rc0 G
System.err.println("文件下载结束！"); '3]p29v{
} g[ 0<m#"
catch(Exception e){e.printStackTrace ();} v0Dq@Q1
} &c(WE RW?-
$mmup|;(
>SN|?|2U/
//获得文件长度 9Etz:?)b
public long getFileSize() iI@jZVk
{ 02`$OTKz
int nFileLength = -1; G&xo1K]
try{ hv6@Jr3
URL url = new URL(siteInfoBean.getSSiteURL()); _Y=2/*y^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <^~FLjsfg
httpConnection.setRequestProperty("User-Agent","NetFox"); .?p\n7
/&& 2u7*
do-ahl,
int responseCode=httpConnection.getResponseCode(); P&d"V<
if(responseCode>=400) b*;"q9u5
{ w;}@'GgL
processErrorCode(responseCode); 6$a$K,dZ
return -2; //-2 represent access is error $WYbm}j
} I$NhXZ)KT
a07@C
tkQH\5
String sHeader; =~Ynz7 /x
)#a[-.OI
JXG"M#{
for(int i=1;;i++) &zQ2M#{82
{ <Llp\XcZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (Rk_-9_E.
//Utility.log(in.readLine()); scuHmY0
sHeader=httpConnection.getHeaderFieldKey(i); ,P'P^0qJ
if(sHeader!=null) >&g}7d%
{ '}g*!jL
if(sHeader.equals("Content-Length")) QIN."&qC^
{ ri`R<l8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $@d9<83=
break; wiaX&-c]8
} IM$2VlC
} w{~+EolK
else ms($9Lv/
break; nzjkX4KV
} O%1v)AT&\
} ^JI o?R
catch(IOException e){e.printStackTrace ();} i,V;xB2
catch(Exception e){e.printStackTrace ();} nJRS.xs
mS#zraJn5
ccCzu6
Utility.log(nFileLength); %N;!+ ;F_g
Z3k(P
/vY_Y3k#
return nFileLength; !3mA0-!+
} I -Xlx<
6:U$w7P0 e
=ji1S}e~p
//保存下载信息（文件指针位置） lPLz@Up~
private void write_nPos() _|72r}j
{ 2fU$J>Y
try{ OA:%lC!
output = new DataOutputStream(new FileOutputStream(tmpFile)); {T"0DSV
output.writeInt(nStartPos.length); h2ZkCML
for(int i=0;i<nStartPos.length;i++) |/gW_;(
{ -~eJn'W
// output.writeLong(nPos); mcz+P |
output.writeLong(fileSplitterFetch.nStartPos); f:g,_|JD$
output.writeLong(fileSplitterFetch.nEndPos); d=,%=@
} 1h*)@
output.close(); 9ukg}_Hx
} ]M)O YY
catch(IOException e){e.printStackTrace ();} 1)}=bhT
catch(Exception e){e.printStackTrace ();} 2&+#Vsm`V
} Auy_K?he]
ZcuA6#3B
J7C4V'_
//读取保存的下载信息（文件指针位置） P5lqSA{6
private void read_nPos() H$af/^
{ =#mTfJ
try{ kOvDl!^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tvXW
int nCount = input.readInt(); #j@71]GI
nStartPos = new long[nCount]; V{|}}b?w?
nEndPos = new long[nCount]; mh<=[J,%p
for(int i=0;i<nStartPos.length;i++) ZKg{0DY
{ Ca%g_B0t
nStartPos = input.readLong(); }SIGPVM
nEndPos = input.readLong(); oG$)UTzGc
} LlBN-9p
input.close(); 0-LpqX
} e*+FpW@
catch(IOException e){e.printStackTrace ();} =%zLh<3v
catch(Exception e){e.printStackTrace ();} `/Nm 2K
} yq+!czlZ
Z/^ u
&a/__c/l
private void processErrorCode(int nErrorCode) USN8N (
{ r>jC_7
System.err.println("Error Code : " + nErrorCode); tbnH,*
} ~gz^Cdh
fN"(mW>!
;q0uE:^S
//停止文件下载 tBTTCwNT%
public void siteStop() 2_Wg!bq
{ 64-#}3zL
bStop = true; xEuN
for(int i=0;i<nStartPos.length;i++) T#pk]c6Q
fileSplitterFetch.splitterStop(); `%3/
DK0.R]&4(
7bxA]s{m
} \A`hj~
} 4tSv{B/}
//负责部分文件的抓取 7Cjd.0T=(
**FileSplitterFetch.java sH[ -W-
*/ I\qYkWg7
package NetFox; K[chjp!$l
pT?Q#,fh
0A{/B/r
import java.io.*; #YDr%>j
import java.net.*; nC {K$
g*w<*
K78rg/`
public class FileSplitterFetch extends Thread { 86f2'o+
CF|]e:
*&Z7m^`FQ
String sURL; //File URL WvHw{^(lF
long nStartPos; //File Snippet Start Position (HoqR
long nEndPos; //File Snippet End Position i&8FBV-
int nThreadID; //Thread's ID PA6=wfc
boolean bDownOver = false; //Downing is over mAk{"65V
boolean bStop = false; //Stop identical .qk]$LJF7
FileAccessI fileAccessI = null; //File Access interface <o2r~E0r3
A]L%dFK
??hJEE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %+ZJhHT
{ $,xnU.n
this.sURL = sURL; bqanFQj
this.nStartPos = nStart; O4<g%.HC6
this.nEndPos = nEnd; Ev!{n
nThreadID = id; @|a>&~xX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P;PQeXKw
} iR$<$P5
K^r)CCO
E,n}HiAz7V
public void run() ]d[ge6
{ $8l({:*q0
while(nStartPos < nEndPos && !bStop) Wlh~)
{ B*htN
R(j1n,c]
D@EO=08<b
try{ ,Ma.V\T[
URL url = new URL(sURL); U|G|l|Bl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c:83LZ
httpConnection.setRequestProperty("User-Agent","NetFox"); vd`}/~o
String sProperty = "bytes="+nStartPos+"-"; PX|=(:(k
httpConnection.setRequestProperty("RANGE",sProperty); q P ;A}C
Utility.log(sProperty); mj?16\|]
y]%w)4PS
N8KQz_]9I
InputStream input = httpConnection.getInputStream(); 9;yn}\N `
//logResponseHead(httpConnection); d2X[(3
4`#F^2r!
EL3|u64GO
byte[] b = new byte[1024]; IPuA#C
int nRead; ?Z\Yu'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .I3?7
{ E^w:KC2@
nStartPos += fileAccessI.write(b,0,nRead); 5q@LxDy,b
//if(nThreadID == 1) D .vw8H3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bh&Ew
} {;2i.m1
<lr*ZSNY
ozsxXBh-`'
Utility.log("Thread " + nThreadID + " is over!"); {F&-7u0
bDownOver = true; 2A4FaBq"
//nPos = fileAccessI.write (b,0,nRead); +Taa!hfys
} [NnauItI
catch(Exception e){e.printStackTrace ();} 1Xy]D
} @|yeqy_:
} dQezd-y*
JT[*3h
0"pVT%b
//打印回应的头信息 QbhW!9(,
public void logResponseHead(HttpURLConnection con) +@X5!S6
{ GC8}X;((Y
for(int i=1;;i++) 5CAR{|a
{ {|9}+ @5Q1
String header=con.getHeaderFieldKey(i); S)He$B$pp
if(header!=null) HEK-L)S. *
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +.[\g|G
Utility.log(header+" : "+con.getHeaderField(header)); 0ZAj=u@O
else QbYc[8-[
break; ,1Qd\8N9
} m}VM+=
} i5hD#
G@S&1=nj3
~;-9X|
public void splitterStop() 9?+9UlJ7K
{ mzL[/B#>M
bStop = true; ;??ohA"{5
} NGjdG=,
E_$z`or
'f?.R&sCA
} JU0]Wq<^[
%R_{1GrL'c
m$>iS@R
/* =fc:6JR
**FileAccess.java ^ L:cjY/
*//文件访问(定位，写) zH)_vW
package NetFox; 9-*NW0
import java.io.*; ~Y5l+EF#
V6iL5&
QhGXBM
public class FileAccessI implements Serializable{ qZ2&Xw.{1
ScnY3&rc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 toa-Wa{
RandomAccessFile oSavedFile; @^nu#R
long nPos; jRkC/Lw
h~HB0^|
5''*UFIF1
public FileAccessI() throws IOException B_3QQtjAl
{ }|8*sk#[
this("",0); <v]9lw'
} upn8n vy4(
T!q_/[i~7
O]u",J5
public FileAccessI(String sName,long nPos) throws IOException <2Y0{ 8)
{ XL< )v_
oSavedFile = new RandomAccessFile(sName,"rw"); '|K.k6
this.nPos = nPos; {'3D1#SK
oSavedFile.seek(nPos); /dHs &SU,
} _45cH{$sA
;cP8?U
$B\E.ml.
public synchronized int write(byte[] b,int nStart,int nLen) wuK=6RL
{ !oSLl.fQd
int n = -1; yM$J52#d#
try{ QrjDF>
oSavedFile.write(b,nStart,nLen); =v2%Vs\7k
n = nLen; ^^LjI
} c cG['7
catch(IOException e) ?#[)C=p]z
{ r7z6___
e.printStackTrace (); #;j9}N
} 2/Nq'
XDmbm*~i
v+q<BYq
return n; xe:' 8J6L
} 2bQ/0?.).-
b;vNq
DnyYMe!r
} u*R7zY
VyZV(k
A!HK~yk~Q
/* ?z.Isvn
**SiteInfoBean.java g{ (@uzqG
*/ Xz1c6mX|o
package NetFox; |$w*RI0C
c>MY$-PD
gA +:CgQ
public class SiteInfoBean { E2:D(7(;l
{g=b]yg\o
;~ee[W$1
private String sSiteURL; //Site's URL : ^(nj7D
private String sFilePath; //Saved File's Path kyAs'R@z
private String sFileName; //Saved File's Name !A-;NGxE
private int nSplitter; //Count of Splited Downloading File u~Lu<3v
QT}iaeC1i
-uR{X G. D
public SiteInfoBean() RjtC:H&XZ
{//nSplitter的缺省值为5 g~R/3cm4
//default value of nSplitter is 5 22bT3
this("","","",5); 02M7gBS
} twbcuaCTW
rt;gC[3\
%Rn:GK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (4ZLpsbJ
{ 59MR|Jt
sSiteURL= sURL; s>J3\PC
sFilePath = sPath; 9S"N4c>
sFileName = sName; "o==4?*L
this.nSplitter = nSpiltter; c%yh(g
Em9my2oE
}~GV'7d1
} t'Htx1#Zc[
g^n;IE$B
yy))Z0E5
public String getSSiteURL() 3:O+GQ*
{ >0M:&NMda
return sSiteURL; wy\o*P9mG)
} C zpsqTQ
Ps|QW
VS%@)sI|Z
public void setSSiteURL(String value) y3AL)
{ Si[eAAd' :
sSiteURL = value; f-s~Q4
} 1l~.R#WG&
:7k`R62{
X@eg<]'m
public String getSFilePath() yI *M[0
{ * T\>
return sFilePath; ZnQ27FcW
} |WUA1g
{'&8`d
K.r!?cfv
public void setSFilePath(String value) l [x%I
{ =Y:5,.U
sFilePath = value; - Ra\^uz
} q>c+bo 6
U0zW9jB
&7lk2Q\
public String getSFileName() DZF[dxH
{ ,&4zKm
return sFileName; vB]3Xb3a
} 0yKwH\S
f};!m=b
#Xj;f^}/
public void setSFileName(String value) 1.uUMW
{ I"~xDa!
sFileName = value; }q/(D?
} r$Yh)rpt:
m*OLoZVy
4$qNcMdz
public int getNSplitter() `s#sE.=o
{ aKaR
return nSplitter; '"'D.,[W2
} .$n$%|"H-
sf<Q#ieTxY
4|I7:~
public void setNSplitter(int nCount) i=x.tsJ:hB
{ Q>##hG:m
nSplitter = nCount; p3{x<AO/
} #IH<HL)t%e
} dw'<"+zO
Sa(yjF1
.ou!g&xu
/* 1y_fQ+\2A
**Utility.java m*Q[lr=
*/ " &_$V@S
package NetFox; u4`mQ6
5@GD} oAn6
bEoB;]
public class Utility { 49iR8w?k
:<'i-Ur8
jsK|D{m?
public Utility() h[Ndtq>3{
{ 82G lbd)
pil0,r $D
*#ob5TBq[
} H5 p}Le
hr)+Pk
//线程睡眠 ]}UeuF\
public static void sleep(int nSecond) jh<TdvF2$
{ U-wq- GT
try{ '7S!6kd?
Thread.sleep(nSecond); Wq=ZU\Y
} [=]+lei
catch(Exception e) e;&{50VY
{ L:|X/c9r[
e.printStackTrace (); f}Ne8]U/Hc
} yv6Zo0s<J
} F[o+p|nF
Ba"^K d`
//日志 4?P%M"\Iv
public static void log(String sMsg) y^EF<<\
{ qK9L+i
System.err.println(sMsg); XwHu:v'=
} }a #b$]Y
F]URf&U
2XETQ;9
public static void log(int sMsg) JxMyeo%gv
{ m<X#W W)N
System.err.println(sMsg); (R;) 9I\
} <wd4^Vr!2
} I>YtWY|ed
r?Zy-yQ
N+C%Z[gt[
/* !%Z)eO~Z
**TestMethod.java Tb!B!m
*/ h=iA;B^>
package NetFox; R"9oMaY
a`[?,W:q
m<,y-bQ*(
public class TestMethod { 34+)-\xt:
mCC:}n"#
s&_IWala
public TestMethod() B4\:2hBq
{ ///xx/weblogic60b2_win.exe oneSgJ
try{ 8a":[Q[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v ,G-k2$Qe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); laD.or
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ul7pxzj
fileFetch.start(); }K#&5E
} l7D4`i<F
catch(Exception e){e.printStackTrace ();} L_.xr ?
"S{6LWkD
QvK]<HEr
} kw}ISXz v
,,wyydG
~'Qpf 8)
public static void main(String[] args) ]'1N_m]?
{ p)[BB6E
new TestMethod(); ,,C~j`F
} RB$ 8^#
} %DND&0`
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