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)); Dl2`b">u
} Bn 5]{Df
for(int i=0;i<nEndPos.length-1;i++) =N5~iMorD-
{ #@QZ
nEndPos = nStartPos[i+1]; zoUM<6q
} )zzK\I6/EQ
nEndPos[nEndPos.length-1] = nFileLength; hP1H/=~
} x4&<Vr
} =@F1J7
Lb2bzZbhx
K/+Y9JP9
//启动子线程 =}6yMR!4R<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6tC0F=
for(int i=0;i<nStartPos.length;i++) y6bl&_
{ /T53"+7:0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {=5Wi|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e_Ue9c.}
nStartPos,nEndPos,i); gZI88Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8{@0p"re@
fileSplitterFetch.start(); =.Tc l"O[
} %jgB;Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }0&@J'<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5.KhI<[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", umt*;U=
nEndPos = " + nFileLength); 2WK]I1_
// fileSplitterFetch[nPos.length-1].start(); i$GL]0
Cpm&w?6
r~&[Gaw
//等待子线程结束 Q Q3a&
//int count = 0; g]sc)4
//是否结束while循环 n*UD0U}`
boolean breakWhile = false; -RisZ-n*
r2WW}W
r &<sSE;5
while(!bStop) 9A@/5Z:v5W
{ 8U98`# i
write_nPos(); g%P6f
Utility.sleep(500); s<f<:BC
breakWhile = true; ;<j[0~qp:
?Vy%<f$
lV4|(NQ9
for(int i=0;i<nStartPos.length;i++) vkFq/+'U
{ eI%{/>
if(!fileSplitterFetch.bDownOver) MGt[zLF9
{ sp=;i8Y 3
breakWhile = false; 8.9Z0
break; tVB9kxtE
} C,2k W`[V
} 0+\%os V
if(breakWhile) %r1NRg8
break; c7~+5
: MfY8P)
-@6R`m=>
//count++; ^lB=O
//if(count>4) kj$Ks2!W
// siteStop(); Hs}3c R}
} k[{h$
Fx6c*KNX3
=l7@YCj5c
System.err.println("文件下载结束！"); ?X'm>R. @
} 2pKkg>/S
catch(Exception e){e.printStackTrace ();} G?p !*7N
} rb"J{^
4f)B@A-
P!c.!8C$
//获得文件长度 ]LcCom:]
public long getFileSize() 4=BIYC"Lu
{ q5@N//<DNN
int nFileLength = -1; )Z.v fc
try{ 3sh}(
URL url = new URL(siteInfoBean.getSSiteURL()); 2P`Z>_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :5YL!D/&
httpConnection.setRequestProperty("User-Agent","NetFox"); DZ-2Z@{PX
C;mcb$@
Pv- i.
int responseCode=httpConnection.getResponseCode(); reBAxmt
if(responseCode>=400) ~pv|
{ %T~3xQ
processErrorCode(responseCode); MBeubS
return -2; //-2 represent access is error Wu}84W"!.V
} 16J"QUuG
><t4 f(d
8>\tD
String sHeader; /0.m|Th'm
A_:CGtv:
Mm&#I[:
for(int i=1;;i++) ECZ`I Z.
{ $N;Nvp2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <$"
//Utility.log(in.readLine()); U]o
sHeader=httpConnection.getHeaderFieldKey(i); zJ"`40V*;
if(sHeader!=null) U=kPxe
{ Kc3BVZ71
if(sHeader.equals("Content-Length")) ? Zhnb0/
{ Gr),o6}p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S.4gfY
break; DlMT<ld
} | e?:Uq
} ^~ 95q0hq:
else 5_H`6-q
break; >}"9heF
} -nHt6AbqP
} K:<j=j@51
catch(IOException e){e.printStackTrace ();} [w1 4hHnq
catch(Exception e){e.printStackTrace ();} pXoD*o b
ktA5]f;
x6qQ Y<>
Utility.log(nFileLength); Whd\Ub8(
u~]O #v
8zI*<RX.Q
return nFileLength; n'5LY9"
} ;2k!KW@
o)V@|i0Js
Z9)-kRQz=r
//保存下载信息（文件指针位置） EE{]EW(
private void write_nPos() *F^t)K2
{ /h(bMbZ
try{ 4#^E$N:
output = new DataOutputStream(new FileOutputStream(tmpFile)); DN$[rCi7
output.writeInt(nStartPos.length); 6rP?$mn2
for(int i=0;i<nStartPos.length;i++) prk@uYCa =
{ Wx:He8N] H
// output.writeLong(nPos); uht>@ WSg|
output.writeLong(fileSplitterFetch.nStartPos); Bn4wr
output.writeLong(fileSplitterFetch.nEndPos); '{ $7Dbo
} f>!H<4 ]
output.close(); +u[^@>_I0
} I2&R+~ktR
catch(IOException e){e.printStackTrace ();} hy]8t1894
catch(Exception e){e.printStackTrace ();} at )m*
} 2FE13{+f
{%&!x;%
59@PY!c>
//读取保存的下载信息（文件指针位置） x+Ws lN2a
private void read_nPos() CVAX?c{
{ 2]UwIxzR
try{ r.JM!x8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p0|PVn.^h
int nCount = input.readInt(); 5qL;@Y
nStartPos = new long[nCount]; znkc@8_4
nEndPos = new long[nCount]; p=d,kY
for(int i=0;i<nStartPos.length;i++) ?!Wh ^su-
{ fi tsu"G
nStartPos = input.readLong(); L!c.1Rf_
nEndPos = input.readLong(); \z8j6 h
} JeXA*U#
input.close(); -T8'|"g
} 0^25uAD=
catch(IOException e){e.printStackTrace ();} 3+4U?~^k*
catch(Exception e){e.printStackTrace ();} G'<Ie@$6l
} riu_^!"Z_
~p!=w#/
qydRmi
private void processErrorCode(int nErrorCode) P-_2IZiz
{ _qf$dGqc
System.err.println("Error Code : " + nErrorCode); p[8H!=`K
} _g]h \3
=e"RE/q2
_, r6t
//停止文件下载 !q[r_wL
public void siteStop() (R|_6[zy
{ )4;$;a1
bStop = true; mD_sf_2>
for(int i=0;i<nStartPos.length;i++) "Q.KBX v/
fileSplitterFetch.splitterStop(); n|'}W+
dsG:DS`q
wZsjbNf`K
} ZWb\^N
} *K'#$`2
//负责部分文件的抓取 +=Y$v2BZA3
**FileSplitterFetch.java -d]v6q'1
*/ 0 /)OAw"m
package NetFox; 9$WA<1PK+
#PGpB5vnaA
( d1ho=
import java.io.*; NcyE_T
import java.net.*; i$g6C
Fp(-&,L0fc
zLSha\X
public class FileSplitterFetch extends Thread { VD90JU]X<
m5%E1k$=
TNF+yj-|X:
String sURL; //File URL iI$;%uY3g
long nStartPos; //File Snippet Start Position k fY0u
long nEndPos; //File Snippet End Position wu;^fL
int nThreadID; //Thread's ID w?JM;'<AYQ
boolean bDownOver = false; //Downing is over 8=,?Bh".
boolean bStop = false; //Stop identical Ro.br:'Bw
FileAccessI fileAccessI = null; //File Access interface }Ryrd!3bY
[l*;+N+
Ewa/6=]LA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &`2$,zX#
{ c9ea%7o{0a
this.sURL = sURL; _X~xfmU
this.nStartPos = nStart; }Sh3AH/
this.nEndPos = nEnd; bcUa'ZfN<
nThreadID = id; }PX8#C_P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M6lNdK
} `G<|5pe
B42qiV2/k
P0l.sVqL
public void run() *EF`s~
{ :+v4,=fHy
while(nStartPos < nEndPos && !bStop) d:g0XP
{ 2rrC y C
X_(n
jMP;$w
try{ IQyw>_~]
URL url = new URL(sURL); m/"}Y]n!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LrhQG
httpConnection.setRequestProperty("User-Agent","NetFox"); W0LJXp-v
String sProperty = "bytes="+nStartPos+"-"; t&MLgu
httpConnection.setRequestProperty("RANGE",sProperty); suFO~/lRno
Utility.log(sProperty); uC5W1LyI
p&lT! 5P!A
a/gr1
InputStream input = httpConnection.getInputStream(); ,F?O} ijk
//logResponseHead(httpConnection); X8 x:/]/0
E.4 X,
(BZd%!
byte[] b = new byte[1024]; ;BW-ag \9
int nRead; ,L;%-}#$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G8@LH
{ X-F:)/$xG
nStartPos += fileAccessI.write(b,0,nRead); t|v_[Za}Z
//if(nThreadID == 1) -"x25~k!?F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v4W<_ 7L_
} MNH-SQB|
n=%D}W
a9p6[qOcd
Utility.log("Thread " + nThreadID + " is over!"); l*|m(7s
bDownOver = true; @WuG8G
//nPos = fileAccessI.write (b,0,nRead); 8C5*:x9l
} zxy/V^mu
catch(Exception e){e.printStackTrace ();} hEfFMi=a`
} Z#flu Q%V
} ngl8) B
T-.Bof(?w
^dRgYi"(A
//打印回应的头信息 wQrD(Dv(yA
public void logResponseHead(HttpURLConnection con) wiM-TFT~
{ !UX7R\qu|
for(int i=1;;i++) FK,Jk04on
{ wbbr8WiU
String header=con.getHeaderFieldKey(i); ZWy,NN1
if(header!=null) F=V_ACU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JA "
Utility.log(header+" : "+con.getHeaderField(header)); %P`|kPW1
else l/6(V:
break; M*<Bp
} W-ol*S
} F5YHc$3^
=f=,YcRn+
3NlG,e'T2
public void splitterStop() '9Xw_1B
{ OYY_@'D
bStop = true; "kg?Or.
} c\N-B,m&
fR,7l9<%Zp
V6tUijz
} G-G\l?R(
q Qc-;|8
ez^b{s`
/* H JjW
**FileAccess.java (!dwUB
*//文件访问(定位，写) TuMD+^x
package NetFox; ka[%p,H
import java.io.*; @^K_>s9B
[p 8fg!|
$6yr:2Xvt
public class FileAccessI implements Serializable{ XV0t 8#T2
42 &m)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L`0}wR?+
RandomAccessFile oSavedFile; S0mF%"
long nPos; @+^5ze\
a+p_47 xa
U?yKwH^{
public FileAccessI() throws IOException %|gj46
{ ]?j[P=\
this("",0); =y1/V'2E
} GoRSLbCUR
P:tl)ob
a3(q;^v
public FileAccessI(String sName,long nPos) throws IOException H_+!.
{ 6ZwFU5)QE/
oSavedFile = new RandomAccessFile(sName,"rw"); D3kx&AR
this.nPos = nPos; etLA F
oSavedFile.seek(nPos); a?ii)GGq
} w@\quy:
t?cO>4*|
XCku[?Ix
public synchronized int write(byte[] b,int nStart,int nLen) [iT#Pu5
{ 6j=a
int n = -1; rw]*Nxgr
try{ ]{E{ IW8
oSavedFile.write(b,nStart,nLen); 3&vUR(10
n = nLen; 4 n\dh<uY
} ,L,?xvWG
catch(IOException e) X~5kgq0"
{ 6$"0!fl>
e.printStackTrace (); DeL7sU
} oB]
U0t~H{-H
F!qt#Sw!\
return n; >aV Q
} ^q ?xi5w
(vqI@fB';u
SSG}'W!z
} OBJk\j+Wi
4?F7%^vr
y|E{]
/* 6=xbi{m$
**SiteInfoBean.java \IG"Te
*/ 4'ymPPY
package NetFox; Xv1mjHZCC
JYU0&nZl4
=/]d\JSp
public class SiteInfoBean { ,6FmU$ Kn
,c\3b)ax
f MDM\&f
private String sSiteURL; //Site's URL 3-Xc3A=w
private String sFilePath; //Saved File's Path C!r9+z)<
private String sFileName; //Saved File's Name 6Jf\}^4@k
private int nSplitter; //Count of Splited Downloading File h(VF
p 6FPdt)
W2\Q-4D
public SiteInfoBean() TWFi.w4pY
{//nSplitter的缺省值为5 ^@0-E@ {c
//default value of nSplitter is 5 +r 2\v
this("","","",5); WSPlM"h
} `&-)(#
1Ev#[FOc
t/9,JG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y 2v69nu~q
{ ~Q)137u]P
sSiteURL= sURL; 8!uqR!M<C
sFilePath = sPath; 'WW['
sFileName = sName; crdp`}}
this.nSplitter = nSpiltter; h#iFp9N
ZT;:Hxv0N
;\5^yDv[e
} ssy+x;<x,
[rt+KA
M)oJ06`K
public String getSSiteURL() %7*Y@k-)o
{ 5%E.UjC
return sSiteURL; 47c` ) *Hc
} ^,.G<2Kx&
kTLA["<m
!z.C}n5F
public void setSSiteURL(String value) }4n?k'_s?
{ d\{#*{_A
sSiteURL = value; @94_'i7\
} >v DD.
'<YVDB&-d,
_(<D*V[
public String getSFilePath() 9-9:]2~g!
{ bl)iji`]
return sFilePath; FGP~^Dr/
} 68^5X"OGF
m%hUvG| i
q3s +?&
public void setSFilePath(String value) t,2Q~ied=
{ faVR %
sFilePath = value; `Oc`I9
} A%G \ AT
'h6Vj6
Gv};mkX[N
public String getSFileName() u,6 'yB'u
{ p2UZqq2
return sFileName; 'e(`2
} N8>;BHBV!
ktr l|
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public void setSFileName(String value) v<`1z?dch
{ EQ j2:9f
sFileName = value; f V|Zh
} GoGo@5n(Z
i*JbFukG
Q7]VB p4
public int getNSplitter() }Dig'vpMx
{ wb>>bV+U
return nSplitter; ;b""N,
} myj^c>1Iz
U 6y ;V
k-(hJ}N
public void setNSplitter(int nCount) N2"4dVV;
{ OudD1( )W
nSplitter = nCount; cN>z`xl
} ZZa$/q"
} 9xvE?8;M#
q1nGj
'ErtiD
/* o6$Q>g`]
**Utility.java 3f{%IU(z
*/ 6'M"-9?G
package NetFox; 7]q$sQ
hwmpiyu
4g#pQ
public class Utility { oy-Qy
a/.O,&3
eTc0u;{V
public Utility() )p MZ5|+X
{ VK+#!!Ha
z^/aJ@gQ
>Hr0ScmN@"
} (YjY=F
Uv6#d":f;
//线程睡眠 f.gkGwNk
public static void sleep(int nSecond) 7/;Xt&
{ =W9;rQm
try{ k!]Tg"]JAh
Thread.sleep(nSecond); wR;_x x
} ]FLuiC
catch(Exception e) W"mkNqH
{ %$ ^yot
e.printStackTrace (); edPnC {?s
} _|MY/SN4A
} j.GpJDq
/tno`su;
//日志 4QnJ;&~
public static void log(String sMsg) Pl=X<Bp
{ OC'cP[$ _
System.err.println(sMsg); H~c+L'=
} dG|srgk+
!U$ %Jz
~9qDmt,i
public static void log(int sMsg) |52VHW8c
{ vm+EzmO,!
System.err.println(sMsg); BCya5!uy
} _Gy*";E
} AM}-dKei|
GYiUne$
31|Vb
/* I\sCH
**TestMethod.java (r,RwWYm
*/ #jV6w=I
package NetFox; Mi\f?
KM|[:v
S<Q6b_D
public class TestMethod { >P5 EW!d
Dyp'a
-aGv#!aIl
public TestMethod() FXFQ@q*}v
{ ///xx/weblogic60b2_win.exe YTq>K/
try{ uH]n/Kv1,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /Mf45U<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LiJ;A*
SiteFileFetch fileFetch = new SiteFileFetch(bean); io:?JnQSA
fileFetch.start(); WKpHb:H
} .N]^g#
catch(Exception e){e.printStackTrace ();} pTmG\wA~$
+D1;_DU
+bd/*^
} MQ"<r,o?:
9Dd/g7
}6eWdm!B
public static void main(String[] args) n$}c+1
{ a2iaP
new TestMethod(); jHB,r^:'
} bdqo2ZO
} lN1T\
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