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)); &qP&=( $
} u;qBW uO
for(int i=0;i<nEndPos.length-1;i++) xui.63/
{ 0 ))W [
nEndPos = nStartPos[i+1]; +MfdZD
} Sc zYL?w^
nEndPos[nEndPos.length-1] = nFileLength; GwoN=
} le-Q&*
} 24 i00s|#
A<VNttgG
amn\#_(
//启动子线程 *g<D p2`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n_/_Y>{M0
for(int i=0;i<nStartPos.length;i++) hVB^:
{ P+~{q.|._c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vA*Ud;%R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MZX-<p+
nStartPos,nEndPos,i); }G#TYF}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3i'L5f67
fileSplitterFetch.start(); Xn'{g
} }qf)L.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .*s1d)\:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dt(#|8i%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rx22W:S=C.
nEndPos = " + nFileLength); ,wN>,(
// fileSplitterFetch[nPos.length-1].start(); ?m?DAd~ZY
02_%a1g
U]Vu8$W
//等待子线程结束 <y}`PmIM I
//int count = 0; Qf|=xV,F
//是否结束while循环 /{';\?w
boolean breakWhile = false; 2,Og(_0>
f@%H"8w!
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while(!bStop) C]tHk)<|42
{ p<2A4="&
write_nPos(); t@TBx=16
Utility.sleep(500); '@ym-\,
breakWhile = true; w7?&eF(w(
&ESE?{of)
SG{> t*E
for(int i=0;i<nStartPos.length;i++) ;L5'3+U
{ n'yC-;
if(!fileSplitterFetch.bDownOver) SJRiMR_F~
{ f<V#Yc(U}
breakWhile = false; :1eJc2o
break; 5m`@ 4%)zp
} WdGjvs
} ]F5qXF5
if(breakWhile) 5{Xld,zw
break; $Q[a^V~:
^;b$`*M1
`43`*=
//count++; 8Q&hhmOnz
//if(count>4) wr/Z)e =^3
// siteStop(); ][|)qQ%V
} 06 kjJ4
`[<j5(T
G] -$fz
System.err.println("文件下载结束！"); .`OyC'
} b{C3r3B8
catch(Exception e){e.printStackTrace ();} 5JE8/CbH
} R$<LEwjSw
8,BNs5
_yq"F#,*
//获得文件长度 :h1-i
public long getFileSize() 0Dj<-n{9
{ ;IC:]Zu
int nFileLength = -1; HB+\2jEE
try{ h\k!X/
URL url = new URL(siteInfoBean.getSSiteURL()); GoI3hp(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]bG8DEwD
httpConnection.setRequestProperty("User-Agent","NetFox"); `zNvZm-E
p!MOp-;-
}xx[=t=nUf
int responseCode=httpConnection.getResponseCode(); IS`1}i$1%
if(responseCode>=400) {%$eq{~m
{ xF'9`y^]!@
processErrorCode(responseCode); FqOV/B /z2
return -2; //-2 represent access is error Y|t]bb
} bJJB*$jW=
m L#-U)?F
!@9Vq6
String sHeader; d&:ABI
~VZ)LQ'7
p$XL|1G*?H
for(int i=1;;i++) fKzOt<wm
{ G2]/g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _ECWSfZ
//Utility.log(in.readLine()); }yup`R
sHeader=httpConnection.getHeaderFieldKey(i); ?*I2?
if(sHeader!=null) z116i?7EnV
{ zkXG%I4h
if(sHeader.equals("Content-Length")) opQ%!["N
{ =,q,W$-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :yN;_bC!b%
break; qEC-'sl<
} U^trZ])
} cD&53FPXC
else B w1ir
break; TFbMrIF
} eHCLENLmB
} jTbJL
catch(IOException e){e.printStackTrace ();} _RT3Fk
catch(Exception e){e.printStackTrace ();} *ip2|2G$
8=rD'*
e_Na_l]
Utility.log(nFileLength); EQDsbG0x
c"w}<8
[hs_HYqJ
return nFileLength; TAbd[:2{F
} CeD O:J=,
pqmS w
byl#8=?
//保存下载信息（文件指针位置） =B9Ama
private void write_nPos() -POV#1s
{ }5~|h%
try{ "oZ-W?IKE
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6-U+<[,x
output.writeInt(nStartPos.length); \F;V69'
for(int i=0;i<nStartPos.length;i++) ,bhOIuep3
{ fZK&h.
// output.writeLong(nPos); E5D5
output.writeLong(fileSplitterFetch.nStartPos); (H/JB\~r
output.writeLong(fileSplitterFetch.nEndPos); pi)7R:i
} w%jc' ;|
output.close(); .i[rd4MCK
} lP*_dt9
catch(IOException e){e.printStackTrace ();} Y4cIYUSc
catch(Exception e){e.printStackTrace ();} x8I=I"Sp
} okfGd= &
}J27Y;Zp9
{-*+G]
//读取保存的下载信息（文件指针位置） :_;9&[H9ha
private void read_nPos() kwRXNE(k]_
{ tz&'!n}
try{ h2g|D(u)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X~ n=U4s}O
int nCount = input.readInt(); $]IX11.m
nStartPos = new long[nCount]; 4.|-?qG
nEndPos = new long[nCount]; <[O8{9j
for(int i=0;i<nStartPos.length;i++) QXZjsa_|
{ s`W\`w}
nStartPos = input.readLong(); 7`;55Se
nEndPos = input.readLong(); ~kUdHne(
} XXsN)2
input.close(); *-~B{2b<
} XQAdb"`
catch(IOException e){e.printStackTrace ();} tZlz0BY!
catch(Exception e){e.printStackTrace ();} *RugVH4
} BgLW!|T[
'=?IVm#C
va \5
private void processErrorCode(int nErrorCode) fZU#%b6G
{ +g8wc(<ik
System.err.println("Error Code : " + nErrorCode); HMyw:?
} ?;!d5Xuu
H^cB?i
<rd7<@>5D
//停止文件下载 i$HA@S
public void siteStop() P6,~0v(S
{ r|t;#
bStop = true; t2Dx$vT*&
for(int i=0;i<nStartPos.length;i++) jE!<]
fileSplitterFetch.splitterStop(); B. Rc s
p!^.;c
2 2K:[K
} 23XSQHVx
} 8s6~l.v
//负责部分文件的抓取 r8\"'4B1
**FileSplitterFetch.java `9QvokD
*/ ad^7t<a}<
package NetFox; \a]JH\T)Q
5~Vra@iab:
`p`)D6
import java.io.*; ~e,k71
import java.net.*; d&K2\n
)SG+9!AbMZ
@T53%v<5
public class FileSplitterFetch extends Thread { =KfV;.&
m1DzUq;
:A%|'HxH3
String sURL; //File URL vJ96qX
long nStartPos; //File Snippet Start Position |0 #J=am
long nEndPos; //File Snippet End Position [iE%P^
int nThreadID; //Thread's ID rblEyCR
boolean bDownOver = false; //Downing is over &6%%_Lw$
boolean bStop = false; //Stop identical 1 FTxbw@
FileAccessI fileAccessI = null; //File Access interface =C{)i@ +
_^cDB1I?
49b#$Xq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s'\PU1{
{ 6u>${}
this.sURL = sURL; bQG2tDvu[
this.nStartPos = nStart; i=$##
this.nEndPos = nEnd; \tf \fa
nThreadID = id; K5-wuD1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lA[BV7.=7
} M&P?/Zi=L
bqEQP3t^
~\A(xmW}
public void run() ()1\b
{ Y<%)Im6v/
while(nStartPos < nEndPos && !bStop) ;ru=z@
{ f\+MnZ4[Qj
,f0|eu>
UJ-IK|P.#
try{ ]i'hCa $$
URL url = new URL(sURL); g:0-`,[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ER0nrTlB<
httpConnection.setRequestProperty("User-Agent","NetFox"); +92/0
String sProperty = "bytes="+nStartPos+"-"; v%O KOrJ
httpConnection.setRequestProperty("RANGE",sProperty); _:oB#-0
Utility.log(sProperty); }3sj{:z{
Y;3DU1MG0
6t9Q,+nJ
InputStream input = httpConnection.getInputStream(); %00KOM:
//logResponseHead(httpConnection); PveY8[i
-r%4,4
c@d[HstBJ
byte[] b = new byte[1024]; 1fBj21zG
int nRead; 6Yw;@w\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cVjs-Xf7D%
{ FncK#hZ.
nStartPos += fileAccessI.write(b,0,nRead); M0[7>N_
//if(nThreadID == 1) |sd0fTK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 94bmKV_
} N"d M+
-a:+ h\K
o HqBNTyH
Utility.log("Thread " + nThreadID + " is over!"); EA.4m3
bDownOver = true; LE^kN<qMK
//nPos = fileAccessI.write (b,0,nRead); W]E6<y'
} ,B|~V 3)(
catch(Exception e){e.printStackTrace ();} 7x8/Vz@\
} oujg( ^E
} Cf@~W)K
Le#>uWM
,CiN@T \&
//打印回应的头信息 0XV8B
public void logResponseHead(HttpURLConnection con) ,PH;j_
{ OwXw9
for(int i=1;;i++) &AR@5M u
{ S<do.{|p[
String header=con.getHeaderFieldKey(i); 1<y(8C6
if(header!=null) =7{n 2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WGwpryaya
Utility.log(header+" : "+con.getHeaderField(header)); sPMCN's
else wLn,x;;<
break; M*M,Z
} ykFm$ 0m+I
} -4du`dg
\;&WF1d`ac
pVgzUu7
public void splitterStop() ;a@%FWc
{ d/I,`
bStop = true; aLZza"W
} uE{r09^q\
~qFuS933
$ ?ayE
} OW}ny
>bQ'*!
| Q0Wv8/
/* qffVF|7
**FileAccess.java fmqHWu*wG
*//文件访问(定位，写) z%ZAN-
package NetFox; "+SnHpNx
import java.io.*; \F`%vZrKR
X2CpA;#;7l
~mAv)JK
public class FileAccessI implements Serializable{ vjNP
jz CA2N%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WI@l2`X
RandomAccessFile oSavedFile; {D6lSj
long nPos; )"W__U0
fpd4 v|(
a=m4)tjk
public FileAccessI() throws IOException ?T.' q
{ %x(||cq
this("",0); Tj0qq.
} u!$+1fI>
90Rz#qrI*
bH6i1c8
public FileAccessI(String sName,long nPos) throws IOException -M\ae
{ ;UU`kk
oSavedFile = new RandomAccessFile(sName,"rw"); jtS-nQ|
this.nPos = nPos; F3)w('h9c
oSavedFile.seek(nPos); gJ \CT'/
} eI20)t`j
)96tBA%u
pZeJ$3@vk
public synchronized int write(byte[] b,int nStart,int nLen) 7T[Kjn^{Oj
{ IR_&dWHyc
int n = -1; ~m`j=ot
try{ 3MqyHOOv
oSavedFile.write(b,nStart,nLen); mbSG
n = nLen; \0)v5u
} r Uau??
catch(IOException e) x-E@[=
{ =}F}XSvXH
e.printStackTrace (); d8N{sT
} TwdY6E3`
Hl"^E*9x
)4O>V?B
return n; $U*b;'o
} (U`<r-n\n
jWpm"C
Vt4KG+zm
} G;jX@XqZ
-l(G"]tRB
i#4}xvi
/* l%\p
**SiteInfoBean.java $I*<gn9
*/ w20)~&LE-
package NetFox; 1n3XB+*
g"}j
9-ei#|Vnt[
public class SiteInfoBean { c_~tCKAZ
nO#a|~-))
|K.J@zW
private String sSiteURL; //Site's URL s~i73Qk/
private String sFilePath; //Saved File's Path @IE.@1
private String sFileName; //Saved File's Name p;xMudM
private int nSplitter; //Count of Splited Downloading File UlNx5l+k
7!;48\O]w
#MyF 1E
public SiteInfoBean() 8wH1x .
{//nSplitter的缺省值为5 ^n%9Tu
//default value of nSplitter is 5 &s0_^5B0
this("","","",5); kac-@
} i;l0)q
/#Gm`BT
5K#<VU*:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )\PPIY>iP
{ qk}Mb_*C)
sSiteURL= sURL; ']C" 'b
sFilePath = sPath; "wi}/,)
sFileName = sName; prw% )#,
this.nSplitter = nSpiltter; `ElJL{Rn
,DIr&5>p2
q.:j yj6
} 7W.z8>p
]^>RBegJBO
\Dx5=Lh
public String getSSiteURL() GeFu_7u!|
{ U-.A+#<IT9
return sSiteURL; N2uTWT>
} |-Q="7b%
k*ZYT6Z?
fG"4\A
public void setSSiteURL(String value) [1Q:
{ AMe_D
sSiteURL = value; ]|8*l]oc
} Bk;/>gD
H tx)MEZ
p)c"xaTP#F
public String getSFilePath() Ha/Gn!l
{ k &6$S9
return sFilePath; SYYg 2I
} ? 4v"y@v
k=
GLiD,QX<
public void setSFilePath(String value) R<Uu(-O-
{ y.aeXlc[
sFilePath = value; LL%s$>c65A
} uB;PaZG?{
SU7 erCHX
L"It0C
public String getSFileName() zgPUW z X=
{ }JM02R~I
return sFileName; ekPn`U
} ,|^ lqY
H=@S+4_bK
y{9<>28
public void setSFileName(String value) [pzo[0G 'v
{ \= G8
sFileName = value; S]<%^W'
} UNCI"Mjb
um=qT)/D
|>dqZ_)v
public int getNSplitter() H|8i|vbi
{ -&0HAtc
return nSplitter; js[H $
} tD+K4 ^
=SK{|fBB
*kq>Z 06'i
public void setNSplitter(int nCount) &\5%C\0Z<
{ A)HV#T`N
nSplitter = nCount; ;@/vKA3l.
} iu+rg(*%
} D8=a+!l-
PS/00F/Ak
FQBAt0
/* [J6q(}f
**Utility.java 4*?JU v
*/ 9t"/@CH{
package NetFox; NaC}KI`
%-O[%Dy
psM&r
public class Utility { JU!vVA_
r!)jxIL\
a+e8<fM yT
public Utility() 9._Osbp3P
{ WoDQg64
^ Iy'<J
E-b3#\^:
} &-(p~[|
9UcSQ"D
//线程睡眠 GcHZ&m4
public static void sleep(int nSecond) WXX08"
{ *6QmYq6c<
try{ c n^z=?
Thread.sleep(nSecond); u= ydX
} Wu U_RE
catch(Exception e) u;H5p\zAzz
{ 6#(rWW"_
e.printStackTrace (); ,H:{twc
} 9Fh1rZD<
} |YK4V(5x
!--A"
//日志 S)z5=N(Xz
public static void log(String sMsg) g6(u6%MD
{ zf?U q
System.err.println(sMsg); a{! 8T
} 0RkiD8U5
=Y<RG"]a&J
nhI1`l&
public static void log(int sMsg) UO8./%'
{ [|dQZ
System.err.println(sMsg); .Eg[[K_iD
} "V:E BR
} O_[]+5.TX
['\u?m
PP!}w
/* r|JZU
**TestMethod.java RtScv
*/ BV512+M
package NetFox; b(?A^a
+I_p\/J?w/
S#f}mb0,
public class TestMethod { }8?1)l
YN($rAkL
9/4Bx!~A
public TestMethod() K91.-k3)$
{ ///xx/weblogic60b2_win.exe Cl'3I%$8K
try{ )+v'@]r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u{(-`Al}L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "bk'#?9
SiteFileFetch fileFetch = new SiteFileFetch(bean); (VH0+
fileFetch.start(); v@;!fBUt
} (g#,AX
catch(Exception e){e.printStackTrace ();} $S{]` +
sA[eKQjaD
-?PXj)<
} -A;4""
'(&,i/O
}q<%![%
public static void main(String[] args) 0\Ga&Q0-(O
{ <O30X !QuK
new TestMethod(); ui4*vjd
} OVf%m~%&s
} (d$ksf_[%f
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