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)); KtArV
} HZ1nuA
for(int i=0;i<nEndPos.length-1;i++) MhJA8|B6|
{ =woP~+
nEndPos = nStartPos[i+1]; dI>cPqQ
} :jC$$oC].
nEndPos[nEndPos.length-1] = nFileLength; A[F_x*S
} mF UsTb]f
} GMB3`&qh
ewWw
<[u(il
//启动子线程 GVfRy@7n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ddd2w
for(int i=0;i<nStartPos.length;i++) 1(RRjT9
{ 1.TIUH1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &Pc.[k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /1$u|Gs *
nStartPos,nEndPos,i); Yq4nmr4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cI/}rZ+
fileSplitterFetch.start(); b"nkF\P@Fj
} f1sp6S0V\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $4qM\3x0,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); reM~q-M~o@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OR37
nEndPos = " + nFileLength); J:O&2g"g
// fileSplitterFetch[nPos.length-1].start(); s_^N=3Si
%@|)&][hO
kUfbB#.5L
//等待子线程结束 %~kE,^
//int count = 0; YY(_g|;?8
//是否结束while循环 {u-J?(s}
boolean breakWhile = false; 6']G HDK
#{#k;va
Ro4!y:2|
while(!bStop) e/#6qCE
{ A/"2a55
write_nPos(); h:sf?X[
Utility.sleep(500); '-Oh$hqCx|
breakWhile = true; U#Iwe=
ovdaK"q2
dBS_N/
for(int i=0;i<nStartPos.length;i++) ~*]7f%L-
{ G9GHBwT
if(!fileSplitterFetch.bDownOver) YB!f=_8
{ W\mgM2p
breakWhile = false; 0)7v_|z
break; 4mtO"'|
} ?$uEN_1O\@
} D,|TQQ
if(breakWhile) uH,/S4?X
break; R(,m!
B-$zioZ
wXZ9@(^
//count++; &9z&#`AY]>
//if(count>4) eu~ u-}.
// siteStop(); ~%eE%5!k
} ZS=;)
q&_\A0
!ZvVj\{
System.err.println("文件下载结束！"); Bjj=UtI
} ~)[pL(4
catch(Exception e){e.printStackTrace ();} IXlk1tHN4I
} 4\k{E-x $
uI&0/
l!W!Gz0to
//获得文件长度 9a_UxF+6/
public long getFileSize() _a|g >
{ /q,=!&f2
int nFileLength = -1; H8B2{]HAt
try{ B&y?Dc
URL url = new URL(siteInfoBean.getSSiteURL()); r!w*y3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %tC[q
httpConnection.setRequestProperty("User-Agent","NetFox"); Iza;~8dH5
SGba6b31
5|>ms)[RQ
int responseCode=httpConnection.getResponseCode(); i)$+#N
if(responseCode>=400) eibkG
{ ~D`R"vzw=
processErrorCode(responseCode); uFhPNR2l
return -2; //-2 represent access is error bj0<A
} Ciz,1IV
5w{U/v$Z
(FZ8T39
String sHeader; ?<Hgq8J
b$_qG6)IJO
p@O,-&/D
for(int i=1;;i++) 6ecx!uc$
{ )8'v@8;-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7GG`9!l]D
//Utility.log(in.readLine()); UH;bg}=8
sHeader=httpConnection.getHeaderFieldKey(i); a`]ZyG*P
if(sHeader!=null) {7MY*&P$,
{ v6|[p
if(sHeader.equals("Content-Length")) /~7M @`1
{ mG@[~w+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RlU?F
break; R>1oF]w
} `ZO5-E
} i,%N#
else Pgq(yPC
break; vpOGyvI
} c&aqN\'4"
} 4:733Q3oK
catch(IOException e){e.printStackTrace ();} m=/HUt3(&0
catch(Exception e){e.printStackTrace ();} mA_EvzXk\
;-l^X%r
|nr;OM
Utility.log(nFileLength); }H saJ=1U
fA0wQz]u
4>H0a
return nFileLength; "*V'
} =CS$c?
[u J<]
[D(JEO@ :
//保存下载信息（文件指针位置） )56L`5#tS
private void write_nPos() gp~-n7'~O
{ _ouZd.
try{ | z_av
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ol<LL#<j4
output.writeInt(nStartPos.length); =knLkbiq7,
for(int i=0;i<nStartPos.length;i++) YcR: _ac
{ nw_|W)JVQ
// output.writeLong(nPos); $Fy~xMA8O
output.writeLong(fileSplitterFetch.nStartPos); 2`ERrh^i"
output.writeLong(fileSplitterFetch.nEndPos); Z![#Uz.z
} aHI~@
output.close(); 3[l\l5'm8
} p]Qe5@NT
catch(IOException e){e.printStackTrace ();} CDW|cr{
catch(Exception e){e.printStackTrace ();} 7~ZG"^k
} SrOv* D3
fIatp
:B|rs&
//读取保存的下载信息（文件指针位置） cXN0D\%`
private void read_nPos() #BS!J&a
{ QfM^J5j.M?
try{ R`@7f$;wG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a8%T*mk(
int nCount = input.readInt(); +|K,\ {'U
nStartPos = new long[nCount]; ~7Nqwwx
nEndPos = new long[nCount]; */TO$ ^s
for(int i=0;i<nStartPos.length;i++) Ae2Y\sAV
{ @Eh(GZN
nStartPos = input.readLong(); XRyeEwA;pp
nEndPos = input.readLong(); m9jjKu]|
} ;i+(Q%LO
input.close(); `Pwf?_2n-
} W=|'&UU Ul
catch(IOException e){e.printStackTrace ();} XuZgyt"=r
catch(Exception e){e.printStackTrace ();} >s,*=a
} V/R@=[
L;b-=mF
(5[#?_~
private void processErrorCode(int nErrorCode) I/v#!`L
{ -(}N-yu
System.err.println("Error Code : " + nErrorCode); NA/Sv"7om
} 3=UufI
iU~d2R+
4K4u]"1
//停止文件下载 ~EYdEqS)
public void siteStop() 9jl\H6JY|
{ |c-`XC2g
bStop = true; C)9-{Yp
for(int i=0;i<nStartPos.length;i++) a"1LF`
fileSplitterFetch.splitterStop(); miCY?=N`
7Bf4ojKt
o(t`XE['<
} &qa16bz
} ZC^?ng
//负责部分文件的抓取 *S4&V<W>
**FileSplitterFetch.java 6+PP(>em
*/ dPgA~~
package NetFox; -ucR@P]
}:0HM8B7!
mcQ\"9;pY
import java.io.*; 6jl{^dI
import java.net.*; (ueH@A"9;
}JT&lyO< b
D6e<1W
public class FileSplitterFetch extends Thread { *1>Tc,mb
_F8-4
U[#q"'P|l
String sURL; //File URL $.B}zY{
long nStartPos; //File Snippet Start Position ~ r$I&8
long nEndPos; //File Snippet End Position Ox'KC
int nThreadID; //Thread's ID % %2~%FVb
boolean bDownOver = false; //Downing is over !yV)EJ:$
boolean bStop = false; //Stop identical 15DlD`QV
FileAccessI fileAccessI = null; //File Access interface {>brue*)
y>RqA*J
j{zVVT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ' 94HVag
{ W}wd?WIps
this.sURL = sURL; icK U)
this.nStartPos = nStart; ?C6`
this.nEndPos = nEnd; \OK}DhY#
nThreadID = id; PKs$Q=Ol<|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ({!*&DVu
} |txzIc.#
'_g*I
Yt4v}{+
public void run() ,l\D@<F
{ M49Hm[0(
while(nStartPos < nEndPos && !bStop) VC!g,LU|-
{ b1ZHfe:
qEjsAL
CR|>?9V
try{ `R$bx 64
URL url = new URL(sURL); {Z[kvXf"mZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ):Ekf2
httpConnection.setRequestProperty("User-Agent","NetFox"); s: MJ{r(s
String sProperty = "bytes="+nStartPos+"-"; $5>x)jr:w+
httpConnection.setRequestProperty("RANGE",sProperty); ,z0E2
Utility.log(sProperty); :!,.c$M
81wmKqDEs
'FN3r
InputStream input = httpConnection.getInputStream(); ^}GR!990
//logResponseHead(httpConnection); H329P*P
yhyh\.
[3W+h1
byte[] b = new byte[1024]; uRw%`J4H
int nRead; Fd9Z7C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "QY~V{u5
{ jH4Wu`r;m
nStartPos += fileAccessI.write(b,0,nRead); 9p"';*{=
//if(nThreadID == 1) wtGb3D"am
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0j{KZy
} a3(f\MMxE
y? 65*lUl
/p@0Q[E
Utility.log("Thread " + nThreadID + " is over!"); MK4CggoC
bDownOver = true; '}NH$ KA
//nPos = fileAccessI.write (b,0,nRead); c-a;nAR
} f<3r;F7
catch(Exception e){e.printStackTrace ();} 0 f"M-x
} >[g'i+{
} 7jF2m'(
t]pJt
&44?k:
//打印回应的头信息 ]^l-k@
public void logResponseHead(HttpURLConnection con) Xc]Q_70O
{ \Ng[lN
for(int i=1;;i++) H0mDs7
{ O,KlZf_B
String header=con.getHeaderFieldKey(i); =TXc- J
if(header!=null) k8"[)lDc.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kc:2ID&
Utility.log(header+" : "+con.getHeaderField(header)); &oiBMk`*
else z[_Gg8e
break; YA^g[,
} ,[Z;"wE
} `#N7ym;s@
a^&3?3
ia/_61%
public void splitterStop() {{_,YO^w
{ !GVxQll[f
bStop = true; ' 9
} & |o V\L
-3:x(^|:K
YcBAW4B`
} fBt7#Tc=U
k$} 6Qd
Tk4"qGC.
/* ~# |p=Y
**FileAccess.java rhvsd2zi
*//文件访问(定位，写) 6T~xjAuJ3T
package NetFox; SYTzJK@vZJ
import java.io.*; rW3fd.;kss
cj/FqU"
gG=E2+=uy
public class FileAccessI implements Serializable{ bDPT1A`F
gs77")K&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /-ky'S9
RandomAccessFile oSavedFile; Z@`HFZJ
long nPos; O8ZHIs
PK* $
b%,`;hy{
public FileAccessI() throws IOException -f:uNF]Ls
{ YEqWTB|w
this("",0); Bhrp"l +|
} :!Tb/1
v4Q8RE?
{z}OZHJN
public FileAccessI(String sName,long nPos) throws IOException ) 4'@=q
{ /1lUFL2D
oSavedFile = new RandomAccessFile(sName,"rw"); g@lAk%V4
this.nPos = nPos; =>6'{32W_
oSavedFile.seek(nPos); 89)rss
} Y,@{1X`0@3
+P<LoI
+<H)DPG<
public synchronized int write(byte[] b,int nStart,int nLen) -.E<~(fad
{ P1ab2D
int n = -1; ]Z\.Vx
try{ R#Bdfmldq
oSavedFile.write(b,nStart,nLen); ;=6~,k)
n = nLen; 3J}bI{3
} #`4ma:Pj
catch(IOException e) jM3{A;U2
{ <&rvv4*H
e.printStackTrace (); YvK8;<k@-?
} ?79ABm a
FiqcM-Af4
R{hKl#j;>
return n; f+huhJS5e
} gI^*O@Q4{b
.gWYKZM
UpS`KgF"v
} PGHl:4`Es!
6l>$N?a
xGeRoW(X
/* Y75,{1\l0
**SiteInfoBean.java RW|3d<Fj
*/ X@)5F 9
package NetFox; {e?D6`#x
mPxph>o
9_F2nmEv
public class SiteInfoBean { :_Y@,CpIEg
GKwm %A
PDo%ob\Ym
private String sSiteURL; //Site's URL eVDI7W:(Sn
private String sFilePath; //Saved File's Path *eytr#0B-
private String sFileName; //Saved File's Name iVt6rX
private int nSplitter; //Count of Splited Downloading File x,z+l-y
NQ!jkojD
q8.K-"f(Q
public SiteInfoBean() MDS;qZx=
{//nSplitter的缺省值为5 *#,wV
//default value of nSplitter is 5 Jx@3zl
this("","","",5); .4~n|d>z
} \0m[Ch}~ey
70L{u+wIy
=x~HcsJ8!R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +)FB[/pXk
{ W9?Vh{w
sSiteURL= sURL; T'l >$6
sFilePath = sPath; {ls$#a+d
sFileName = sName; ^~2GhveBV
this.nSplitter = nSpiltter; 0t1WvW
)sVz;rF<
5/Q^p"
} <ok/2v
,&!Txyye
0Q=4{*:?
public String getSSiteURL() A5zT^!`[
{ 'tp1|n/1
return sSiteURL; vO"Sy{)Z>
} Z| Z447_
!t6:uC7H
ayuj)]b
public void setSSiteURL(String value) A_}F
{ s3W)hU)
sSiteURL = value; x(7K=K']
} m6)8L?B
9Bl_t}0
k#%BxT
public String getSFilePath() mh!;W=|/"
{ <IGQBu#ZH
return sFilePath; 7%9Sz5z
} {SW}S_
Ym5q#f)|
3ADTYt".
public void setSFilePath(String value) ` IiAtS
{ _YY:}'+
sFilePath = value; *?K3jy{
} hp!UW
`ej
# &o3[.)9
public String getSFileName() Q uy5H
{ Kgi%Nd
return sFileName; RiF~-;v&
} qIa|sV\w0
AxUj CerNf
=u(. Y
public void setSFileName(String value) EaG3:<>J
{ n0kBLn
sFileName = value; q3B#rje>h
} _H|x6X1-
|<P]yn
`AeId/A4n
public int getNSplitter() `(<XdlOj
{ u<./ddC
return nSplitter; 9. Q;J#;1
} (t1:2WY@
1"009/|
|r!G(an1x4
public void setNSplitter(int nCount) *?7Ie;)
{ DF/p{s1Y3
nSplitter = nCount; l.?R7f
} MVK='
} el39HB$
dy;Ue5
C".&m
/* ]L%qfy4
**Utility.java z@^l1)m
*/ aHe/MucK
package NetFox; lqa.Nj
a-,!K
0n|op:]BHM
public class Utility { bN@V=C3
ZkkXITQkPM
@kn0f`
public Utility() ^)conSm
{ 5V4Ze;K
z,[4BM
|AW[4Yn>
} P*XLm
K_',Gd4L
//线程睡眠 s={AdQ
public static void sleep(int nSecond) hgX@?WWR
{ 1 e1$x@\\
try{ IL?3>$,
Thread.sleep(nSecond); v{^_3 ]
} wP- pFc
catch(Exception e) f@T/^|`mh
{ ~cVFCM
e.printStackTrace (); deHhl(U;
} DTk)Y-eQ
} \T'uFy9&a
11}X2j~Ww
//日志 h}i /u
public static void log(String sMsg) Pfu2=2Ra
{ }x`W+r
System.err.println(sMsg); K?,eIZ{.S
} g8 ,V( ^
RyKsM.
V03U"eI="
public static void log(int sMsg) ttuQ,SD
{ *g]q~\b/;
System.err.println(sMsg); b"t95qlL
} iXK.QktHw
} ilEWxr;,
3:7J@>
-z./6dQ
/* DcE)6z#
**TestMethod.java e)LRD&Q
*/ uA7~`78
package NetFox; %+YLe-\?
\RyOexNZ
FA<|V!a
public class TestMethod { R<@s]xX_
M5s>;q)
j|TcmZGO
public TestMethod() I4:4)V?
{ ///xx/weblogic60b2_win.exe {v+,U}
try{ \:-#,( .V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S(eCG2gR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P7O$*
SiteFileFetch fileFetch = new SiteFileFetch(bean); )1wC].RFYm
fileFetch.start(); 4eK!1|1
} F0W4B
catch(Exception e){e.printStackTrace ();} S:4'k^E
,3&XV%1
lfp[(Ph)9
} &[$qA
eRc+.m[
Qyvn A|&
public static void main(String[] args) C']TO/2q
{ z^$DXl@)h
new TestMethod(); Yb\t0:_
} nfET;:{
} KWbnSL8
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