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)); U8n=Ro
} Ns.{$'ll
for(int i=0;i<nEndPos.length-1;i++) rXVRX#Lh
{ -!X\xA/KN
nEndPos = nStartPos[i+1]; Ee'wsL
} %[fZ@!B
nEndPos[nEndPos.length-1] = nFileLength; ?A~a}bFZ
} gk4DoOj#P
} 6bUcrw/# p
:CG;:( |
}PzHtA,V
//启动子线程 'Xg9MS&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \/?&W[TF
for(int i=0;i<nStartPos.length;i++) p&ZLd`[
{ H'x_}y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a@N 1"O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c6LPqPcN
nStartPos,nEndPos,i); yS@xyW /
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0yL%Pjn6
fileSplitterFetch.start(); #w;%{C[D
} .>@]Im
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xi=Qxgx0I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Env_??xq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p0C|ECH
nEndPos = " + nFileLength); @<B$LJ|jdG
// fileSplitterFetch[nPos.length-1].start(); &\<?7Qj3U|
jWh}cM=
"\"sM{x
//等待子线程结束 I1!m;5-c9k
//int count = 0; HQV#8G#B
//是否结束while循环 rG{,8*
boolean breakWhile = false; pR3K~bx^
[+b&)jN*2
%^bN^Sq -
while(!bStop) DaqpveKa
{ F,JqHa9
write_nPos(); t8t+wi!
Utility.sleep(500); @!%HEs!# #
breakWhile = true; d?4-"9Y
Fy^MI*}BZ
YBQ{/"v%|
for(int i=0;i<nStartPos.length;i++) ?$%2\"wX~7
{ #LfoG?k1K
if(!fileSplitterFetch.bDownOver) D*!9K8<o
{ %SwhNn
breakWhile = false; DTCOhUIV
break; m]/sR3yF
} =xM:8 hm
} vp`s< ;CA
if(breakWhile) YI),yj
break; #80M+m
nfS.0\z
K7]QgfpSZ
//count++; +P;&/z8i*g
//if(count>4) dU#}Tk
// siteStop(); ,5P tB]8&3
} ^(1S`z$
U$j?2|v-x
B#[.c$
System.err.println("文件下载结束！"); LRv[,]b
} P#qQde/y
catch(Exception e){e.printStackTrace ();} '~[JV>5
} <xr\1VjA
N m@UM*D
/t_AiM,(
//获得文件长度 xRm~a-rp
public long getFileSize() B^"1V{M
{ z460a[Wl
int nFileLength = -1; Mtq^6`JJ'
try{ 2Z*^)ZQB
URL url = new URL(siteInfoBean.getSSiteURL()); KNqs=:i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X>ck.}F
httpConnection.setRequestProperty("User-Agent","NetFox"); '%[r9w
^"EK:|Y4%K
yn.f?[G2
int responseCode=httpConnection.getResponseCode(); <{1=4PA
if(responseCode>=400) VU\{<j{
{ X&cm)o%5Fe
processErrorCode(responseCode); g)^g_4
return -2; //-2 represent access is error 4i(?5p>f
} #\gx.2W7
t? [8k&Z
Y]H,rO
String sHeader; ?=%#lZ&?
0R}F(tjw
nBGcf(BE.$
for(int i=1;;i++) _#TbOfu
{ .@3bz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9AHxa
//Utility.log(in.readLine()); Ae>:i7.V
sHeader=httpConnection.getHeaderFieldKey(i); x^/453Lk
if(sHeader!=null) ?m dGMf)
{ 5ii:93Hlj
if(sHeader.equals("Content-Length")) h"On9
{ ')1p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); yo_;j@BGR
break; (GbZt{.
} x4;ndck%U
} *&~wl(+O=
else </9@RO
break; 0i/!nke.
} {Zrf>ST
} e\'=#Hw
catch(IOException e){e.printStackTrace ();} ^/7L(
catch(Exception e){e.printStackTrace ();} )G@/E^ySM
70yM]C^
peGh-
Utility.log(nFileLength); ;@V1*7y
d^^EfWU
Z'o'd_g>I+
return nFileLength; e~NF}9#A
} ]TIBy "3
]$i~;f 8I
=Bb/Y`Q
//保存下载信息（文件指针位置） TqTz
private void write_nPos() n$y@a?al
{ C^nTLw;K
try{ ($[)Tcq*~
output = new DataOutputStream(new FileOutputStream(tmpFile)); s.XLC43Rs
output.writeInt(nStartPos.length); |oV_7%mlu
for(int i=0;i<nStartPos.length;i++) 9O\N K:2
{ )9z3T>QW
// output.writeLong(nPos); .|<+-Rsj
output.writeLong(fileSplitterFetch.nStartPos); _X]S`e1F
output.writeLong(fileSplitterFetch.nEndPos); |ZJ<N\\h-
} ?qR11A};tG
output.close(); 'uU{.bq
} _e94
catch(IOException e){e.printStackTrace ();} 41NVF_R6J
catch(Exception e){e.printStackTrace ();} %mMPALN]{
} w}r~Wk^dLI
S F&EVRv
Kzrt%DA
//读取保存的下载信息（文件指针位置） L5A?9zum/!
private void read_nPos() Rg~F[j$N
{ m!_*Q
try{ A7=k9|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <K GYwLk
int nCount = input.readInt(); d{:0R9
nStartPos = new long[nCount]; aF%V
nEndPos = new long[nCount]; 7V-'><)gI
for(int i=0;i<nStartPos.length;i++) !7jVKI80
{ dI) 9@UL
nStartPos = input.readLong(); X^9eCj;c
nEndPos = input.readLong(); &M*f4PeXb
} ^Bu55q
input.close(); m$}Jw<.W
} \cW9"e'
catch(IOException e){e.printStackTrace ();} )|j?aVqZ
catch(Exception e){e.printStackTrace ();} %3mh'Z -[f
} iuS*Vw
)T!3du:M
l&oc/$&|[
private void processErrorCode(int nErrorCode) POt8G
{ vbSycZ2M7
System.err.println("Error Code : " + nErrorCode); o2W^!#]=
} eGj[%pk
5Za%EaW%G
g~]?6;uu
//停止文件下载 k07pI<a?
public void siteStop() <_~e/+_.
{ F7IZ;4cp
bStop = true; Q+a"Z^Z|
for(int i=0;i<nStartPos.length;i++) [ %6(1$Ih
fileSplitterFetch.splitterStop(); D2MWrX
nV3I6
a+PVi
} K| '`w.
} W+u-M>Cj6
//负责部分文件的抓取 Y[Eq;a132
**FileSplitterFetch.java IHcR/\mz
*/ Ucd~-D
package NetFox; Qkb=KS%z
55Ag<\7
}b=Cv?Zg$m
import java.io.*; _q=ua;I&
import java.net.*; p}K.-S`MQ
%hCd*[Z}j
$c}-/U 8
public class FileSplitterFetch extends Thread { #8@o%%Fd
2+cpNk$
a<CACWsN.T
String sURL; //File URL 5`p>BJ+n
long nStartPos; //File Snippet Start Position f_'8l2jK1i
long nEndPos; //File Snippet End Position <#~n5W{l
int nThreadID; //Thread's ID *^[j6
boolean bDownOver = false; //Downing is over /a?qtRw
boolean bStop = false; //Stop identical -~v1@
FileAccessI fileAccessI = null; //File Access interface &AP`k
*I9O+/,
dq^vK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +a0` ,Jc
{ *=zv:!
this.sURL = sURL; jzd)jJ0M
this.nStartPos = nStart; M<'He.n
this.nEndPos = nEnd; !q5qA*
nThreadID = id; X}B]0z>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;bRyk#
} >p 9~'
Nx=rw h
]_43U` [#
public void run() ~Aw.=Yi=
{ OZ,Xu&N
while(nStartPos < nEndPos && !bStop) AA<QI'6
{ JasA w7
.X34[AXd
;"|QW?>$D
try{ -rlCE-S
URL url = new URL(sURL); C1o^$Q|j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cG,zO-H
httpConnection.setRequestProperty("User-Agent","NetFox"); R'Uf#.
String sProperty = "bytes="+nStartPos+"-"; fi [4F
httpConnection.setRequestProperty("RANGE",sProperty); %jn)=;\
Utility.log(sProperty); \gR%PN
v"-K-AQjB
<h%I-e6
InputStream input = httpConnection.getInputStream(); 0t7vg#v|
//logResponseHead(httpConnection); Z7p!YTA
8\Bb7*
K/M2L&C
byte[] b = new byte[1024]; A\<W x/
int nRead; pD;fFLvN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W_lXY Z<
{ N5.B"l
nStartPos += fileAccessI.write(b,0,nRead); sW@_' Lw
//if(nThreadID == 1) `G`yA%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bX>R9i$
} ZdgzPs"
xSq{pxX
Z):Nd9
Utility.log("Thread " + nThreadID + " is over!"); }CL7h;5N 3
bDownOver = true; oS^KC}X
//nPos = fileAccessI.write (b,0,nRead); 1$H<Kjsm
} n j2=}6
catch(Exception e){e.printStackTrace ();} -ARks_\
} i!)\m0Wm
} oI-,6G}
**JBZ\'
sO{TGk]*
//打印回应的头信息 iFnD`l6)
public void logResponseHead(HttpURLConnection con) BhhFij4
{ xZA.<Yd^r
for(int i=1;;i++) 1Eb2X}XC
{ b8E7/~<z3
String header=con.getHeaderFieldKey(i); Bk[C=<X
if(header!=null) 0+e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e, fZ>EJ
Utility.log(header+" : "+con.getHeaderField(header)); sLUOs]cj
else hLj7i?
break; +QNsI2t;r
} V!/9GeIF
} */2nh%>$
3OFI>x,h
bEln.)
public void splitterStop() o59b#9
{ }(7TiCwd
bStop = true; \440gH`
} h"nhDART<
R3%%;`c=
*wx95?H0Z
} ERia5HnoD,
?tA%A
f-p$4%(
/* -iKoQkHt
**FileAccess.java _s*p$/V\
*//文件访问(定位，写) .><-XJ
package NetFox; -Aojk8tc
import java.io.*; Y&H<8ez
hZlHY9[t?
B<i(Y1n[
public class FileAccessI implements Serializable{ &gKDw!al
qw1W}+~g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #k?.dWZ!
RandomAccessFile oSavedFile; \&b 9
long nPos; `QtkC>[
+P8CC fPu
)ZI#F]
public FileAccessI() throws IOException Em !%3C1r
{ U.X`z3q
this("",0); +abb[
} $JUkwsc
ja9=b?]0,
Wf^sl
public FileAccessI(String sName,long nPos) throws IOException `mA;1S
{ ]6M,s0
oSavedFile = new RandomAccessFile(sName,"rw"); @yo6w}3+-
this.nPos = nPos; 4EmdQn
oSavedFile.seek(nPos); zc$}4o
} N`?|~g3
3dlY_z=0
NGJst_
public synchronized int write(byte[] b,int nStart,int nLen) (T%?@'\
{ eL~3CAV{
int n = -1; )[oP`Z
try{ b.v +5=)B
oSavedFile.write(b,nStart,nLen); tDRo)z
n = nLen; d%.|MAE
} E- [Eg
catch(IOException e) eh> |m>JY
{ r}es_9*~Z
e.printStackTrace (); YC')vv3o(
} H6{Bx2J1*
'&e8;X
FvY=!U06
return n; ^RO<r}Bu
} } C:i0Q
`hdff0
1YQYZ^11
} AwjXY,2
FzcXSKHV%
zyhM*eM.7
/* oyr b.lu/
**SiteInfoBean.java jXLd#6
*/ o$eCd{HuX
package NetFox; ;mT}Q;F#
q/@+.q
Vjs'|%P7
public class SiteInfoBean { V?1[R
=yz"xWH
#:+F
private String sSiteURL; //Site's URL 1Y*k"[?dW
private String sFilePath; //Saved File's Path yQMwt|C4
private String sFileName; //Saved File's Name Zp^O1&\SK?
private int nSplitter; //Count of Splited Downloading File v/9DD%An
fLqjBG]<
T.3{}230<
public SiteInfoBean() tsL ; wT_
{//nSplitter的缺省值为5 l _%<U
//default value of nSplitter is 5 1O<6=oH
this("","","",5); g4b#U\D@)/
} IdN3Ea]
/ Ws>;0
mvK^')
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y: x<`E=
{ W#~7X
sSiteURL= sURL; kl]MP}wc
sFilePath = sPath; h x&"fe
sFileName = sName; |T@SlNi]
this.nSplitter = nSpiltter; ,}&TZkN{-
v@tEHRadz
:;.^r,QAI
} D\b$$z]q
51b%uz
Y|><Ls6Q
public String getSSiteURL() *U,JQ
{ NS2vA>n8R
return sSiteURL; xYCJO(&
} Yi?bY
g i6s+2
L7;~4_M9.V
public void setSSiteURL(String value) oe]*Q
{ :`zO%h
sSiteURL = value; P%lD9<jED
} s{R,- \_
vhbHt_!u&
3a.!9R>
public String getSFilePath() `DF49YP"~
{ /0H}-i
return sFilePath; Gmi?xGn
} J)Y`G4l2@
e)n ,Y
y;Cs#eo
public void setSFilePath(String value) F`m}RL]g
{ babL.Ua8o
sFilePath = value; :\P@c(c{^C
} 8 E\zjT!#\
PVp>L*|BZ;
:Q>e54]'&
public String getSFileName() p$9Aadi]
{ / Qd` ?
return sFileName; U,#x\[3!Jt
} lQ`=PFh
:>{!%-1Z
H^*AaA9-
public void setSFileName(String value) A6]X aF
{ ~q}L13^k
sFileName = value; (g@\QdH`|
} mdEJ'];AH
0|FxSc
'Og@<~/Xy
public int getNSplitter() e O\72? K
{ fV|uKs(W
return nSplitter; 6!"wiM"]
} ,{HQKHg
k3qQU)
vvv'!\'#
public void setNSplitter(int nCount) v,ZYh w
{ d-B+s%>D
nSplitter = nCount; m6mGcbpn
} __'4Qt
} uL^; i""
xj;:B( i
K<*6E@+i
/* Q}@t'
**Utility.java KhfADqji|
*/ bpwA|H%{M
package NetFox; O|,9EOrP
p?y2j
o13jd NQ-
public class Utility { ")Not$8
|T""v_q
'JMW.;Lh?X
public Utility() ]5"k%v|
{ t<Yi!6
"jum*<QZz
PiKP.
} o@zxzZWg
Gy/w #4xj
//线程睡眠 z qq
public static void sleep(int nSecond) FSA%,b;U
{ \uOM,98xS
try{ '_G\_h}5
Thread.sleep(nSecond); q k^FyZ<
} sWo`dZ\6WB
catch(Exception e) |ZH(Z}m
{ '-%1ILK$3r
e.printStackTrace (); .@,t}:lD
} UmWXv#q\l
} /%& d:
dR]-R/1|
//日志 kP%hgZ
public static void log(String sMsg) UA8hYWRP
{ losqc *|
System.err.println(sMsg); [ @eA o>
} pz /[${X
7?=^0?a
XG.[C>
public static void log(int sMsg) V+"%BrM
{ '%rT]u3U
System.err.println(sMsg); p3U)J&]c6
} Rsfb?${0G
} M9W zsWM
8<C*D".T$
VhkM{O
/* MT&aH~YB
**TestMethod.java |X8?B=
*/ k)n b<JW|r
package NetFox; 6#+&/ "*
|ky40[C
~JXz
public class TestMethod { 2xLtJR4L
1X2j%qI&
?.VKVTX^
public TestMethod() 4[$:KGh3
{ ///xx/weblogic60b2_win.exe _U^[h!
try{ ~9+01UU^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d^}p#7mB\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tS2&S 6u
SiteFileFetch fileFetch = new SiteFileFetch(bean); (kLaXayn
fileFetch.start(); @-)?uYw:r
} UN.;w3`Oc
catch(Exception e){e.printStackTrace ();} * hs&^G
(+|+ELfqW
5I2,za&e
} src9EeiV
oFU:]+.+D
27D*FItc
public static void main(String[] args) g3$'Ghf
{ !{jw!bB
new TestMethod(); [Y](Y3/.N
} )*BZo>"
} @JbxGi
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