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)); 3;MjO*-
} 0^_lj9B!
for(int i=0;i<nEndPos.length-1;i++) EB5_;
{ Hpi%9SAM
nEndPos = nStartPos[i+1]; `n`"g<K)Q
} eQFb$C]R}y
nEndPos[nEndPos.length-1] = nFileLength; 7TkxvSL X
} vM7vf6
} Y#&0x_Z
{Mr~%y4
^2^|AXNES
//启动子线程 5!F\h'E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZBmXaP[9
for(int i=0;i<nStartPos.length;i++) #RM3^]h
{ HNy/ -
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x8?x/xE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5 n+ e
nStartPos,nEndPos,i); {kPe#n>xT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q{cp|#m#G
fileSplitterFetch.start(); 3z)"U
} r1oku0o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $54=gRo^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <D!c ~*[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /3Nb
nEndPos = " + nFileLength); Pc)VK>.fc
// fileSplitterFetch[nPos.length-1].start(); U2V^T'Y[
g[s\~MF@s
/^LH
//等待子线程结束 *)bd1B#
//int count = 0; B9e.-Xaf
//是否结束while循环 |Vwc/9`t]>
boolean breakWhile = false; 8.CKH4h
f[Fgh@4cj
)W]>\=@Y
while(!bStop) 0^9:KZ.!
{ }B"|z'u
write_nPos(); _t|G@D{
Utility.sleep(500); :,NFFN
breakWhile = true; e" Eqi-
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x(9;!4O>
for(int i=0;i<nStartPos.length;i++) Fkcx+d
{ 1a&/Zlr
if(!fileSplitterFetch.bDownOver) 5'X74`
{ K)/!&{7n}a
breakWhile = false; %e Sm&`
break; y98JiNq
} cXS;z.M\_
} W""*hJ
if(breakWhile) O[IR|
break; q*[!>\Z8
19F ;oFp
RQ^m6)BTo
//count++; CYtjY~
//if(count>4) | "Jx
// siteStop(); .QXG"R
} >'aG/(
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X<~k =qwA
System.err.println("文件下载结束！"); 7-".!M
} 6[*;M
catch(Exception e){e.printStackTrace ();} 4[TS4p
} %'L].+$t
djsz!$
K/vxzHSl
//获得文件长度 894r;UA7
public long getFileSize() V(;55ycr
{ m7r j>X Y
int nFileLength = -1; W?qpnPW
try{ x0\e<x9s
URL url = new URL(siteInfoBean.getSSiteURL()); VY/|WD~"CW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j-J(C[[9
httpConnection.setRequestProperty("User-Agent","NetFox"); 48tcgFg[
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`]`=]*d
int responseCode=httpConnection.getResponseCode(); 17>5#JLP
if(responseCode>=400) ]?0{(\
{ Nfv="t9e
processErrorCode(responseCode); K,f* SXM
return -2; //-2 represent access is error \G$QNUU
} 0 kf(g156
+"cRhVR
+ a-wv
String sHeader; C-llq`(d
c ]>DI&$;J
.E+OmJwD
for(int i=1;;i++) "jL1.9%"
{ tJ=3'?T_k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (M ]XNn
//Utility.log(in.readLine()); Dv<wge`
sHeader=httpConnection.getHeaderFieldKey(i); AL>c:K)qO
if(sHeader!=null) 2E$^_YT C
{ 5>k>L*5J
if(sHeader.equals("Content-Length")) wgY6D!Y
{ 9p<:=T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [34zh="o
break; 1ZT^)/G
} Wrmgu}q
} 3A-*vaySV
else >M?H79fF2s
break; !|:RcH[
} $hh+0hs
} 8h2D+1,PZC
catch(IOException e){e.printStackTrace ();} OmB TA=E<
catch(Exception e){e.printStackTrace ();} ,H>W:O
Z6 ;Wd_
O\6vVM[
Utility.log(nFileLength); B!eK!B
oJ^C]E
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return nFileLength; ;0IvF#SJ(.
} jcE Msc
'KH lrmnr
.iFViVZC
//保存下载信息（文件指针位置） ^6Yd}
private void write_nPos() 6\NvG,8
{ -*?p F_*w
try{ swttp`
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]k[x9,IU\y
output.writeInt(nStartPos.length); E W`W~h[
for(int i=0;i<nStartPos.length;i++) jDR')ascn
{ FJ{=2]x|
// output.writeLong(nPos); jz*0`9&_
output.writeLong(fileSplitterFetch.nStartPos); (~h7rAEc
output.writeLong(fileSplitterFetch.nEndPos); BU`ckK\(
} _ w/_(k
output.close(); w4UD/zO
} ^w.]Hd2
catch(IOException e){e.printStackTrace ();} ~p:?QB>1]
catch(Exception e){e.printStackTrace ();} iC\%_5/_
} 4sTMgBzw
j !`B'{cH
ymYBm:"
//读取保存的下载信息（文件指针位置） 'xIyGDe
private void read_nPos() eH %Ja[
{ u^t$cLIZ
try{ }MP>]8Aq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i0>]CJG
int nCount = input.readInt(); tAERbiH
nStartPos = new long[nCount]; OZf6/10O/
nEndPos = new long[nCount]; =~&VdPZ
for(int i=0;i<nStartPos.length;i++) :_v!#H)
{ *r;xw
nStartPos = input.readLong(); &=X.*H%
nEndPos = input.readLong(); UbO4%YHt
} e?b)p5g
input.close(); $E\^v^LW
} }AlYNEY
catch(IOException e){e.printStackTrace ();} :|rPT)yT]
catch(Exception e){e.printStackTrace ();} (-,>qMQs
} TN\|fzj
\w%@?Qik
ziiwxx_
private void processErrorCode(int nErrorCode) $#e1SS32
{ c+g@Z"es
System.err.println("Error Code : " + nErrorCode); ZIDbqQu
} zyFUl%
7CGyC[[T~
.1#kDM
//停止文件下载 [*Uu#9
public void siteStop() Ab2Q \+,
{ {e"dm5
bStop = true; lq>AGw
for(int i=0;i<nStartPos.length;i++) \F{:5,Du)
fileSplitterFetch.splitterStop(); "j^MB)YD
cG{L jt
?IF)+]
} q9]IIv
} +.kfU)6@
//负责部分文件的抓取 P6\6?am
**FileSplitterFetch.java !Ms[eB
*/ cj$d=k~
package NetFox; ,eRQu.
;j9\b9m
ac8P\2{"
import java.io.*; ok{!+VCB5
import java.net.*; vUesV%9hq
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Gh\q^?}
public class FileSplitterFetch extends Thread { }ptq )p
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String sURL; //File URL Uz dc
long nStartPos; //File Snippet Start Position U*)m',
long nEndPos; //File Snippet End Position Hy_;nN+e
int nThreadID; //Thread's ID S1S;F9F
boolean bDownOver = false; //Downing is over UbamB+QT
boolean bStop = false; //Stop identical 5Qh?>n>*
FileAccessI fileAccessI = null; //File Access interface IzLQhDJ1
g(|{')8?d
\tN-(=T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~*W!mlg
{ {Ui=b+
this.sURL = sURL; =]C]=
this.nStartPos = nStart; 5jxQW ;
this.nEndPos = nEnd; N<(.%<!
nThreadID = id; nh>K`+>co
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m P'^%TE
} w= P9FxB
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public void run() Yz$3;
{ QPtGdd
while(nStartPos < nEndPos && !bStop) P [Uy
{ Y!J>U
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try{ e[_m<e
URL url = new URL(sURL); 6Htg5o|W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4k-+?L!/G
httpConnection.setRequestProperty("User-Agent","NetFox"); YuZ"s55zU{
String sProperty = "bytes="+nStartPos+"-"; N- H^lqD
httpConnection.setRequestProperty("RANGE",sProperty); l 'DsZ9y@2
Utility.log(sProperty); @f]{>OS
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w }^ I
InputStream input = httpConnection.getInputStream(); ?`zXLY9q7
//logResponseHead(httpConnection); } :=Tm]S
n_ lo`
&e-U5'(6v_
byte[] b = new byte[1024]; r%:+$aIt
int nRead; h\v'9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,to+oSZE
{ Tm_B^W}
nStartPos += fileAccessI.write(b,0,nRead); b2b?hA'k
//if(nThreadID == 1) om?-WJI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |sRipWh
} Mi'8 ~J
26T"XW'_
8#!i[UFdj
Utility.log("Thread " + nThreadID + " is over!"); ^uv<6
bDownOver = true; mKo C.J
//nPos = fileAccessI.write (b,0,nRead); [ i#zP
} >SPh2[f
catch(Exception e){e.printStackTrace ();} oF(Lji?m
} ;qHOOT
} `W/sP\3
#Zrlp.M4
=] *.ZH#h
//打印回应的头信息 mU}F!J#6
public void logResponseHead(HttpURLConnection con) 4jD2FFG- G
{ {43>m)8+
for(int i=1;;i++) Y%`xDI
{ b[V^86X^
String header=con.getHeaderFieldKey(i); A\8}|r(>9E
if(header!=null) K2%w0ohC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,^#yo6-
Utility.log(header+" : "+con.getHeaderField(header)); KM^ufF2[
else y~()|L[
break; ")=X4]D
} P#=`2a#G
} 8 r_>t2$
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5^^XQ?"
public void splitterStop() >jD[X5Y
{ 4Y[1aQ(%
bStop = true; (}}S9K
} W`c'=c
M Y|w
yX~v-N!X
} s%<eD
[l,Ei?
3}e%[AKh
/* ^o7;c[E`
**FileAccess.java M)SEn/T-
*//文件访问(定位，写) 8#vc(04(
package NetFox; / X1 x
import java.io.*; _a1x\,R|DB
)"pF R4
"~'b
public class FileAccessI implements Serializable{ g)-bW+]q
u*hSj)vr1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >$4d7.^hb/
RandomAccessFile oSavedFile; B ~OZ2-~
long nPos; 720DV+o
R?]02Q
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public FileAccessI() throws IOException i>(e}<i
{ wiiCd
this("",0); ti#7(^j
} -\C!I
i-6Z"b{
~c\e'&sc;
public FileAccessI(String sName,long nPos) throws IOException RsYU59_Y
{ '3g[]M@M
oSavedFile = new RandomAccessFile(sName,"rw"); "s{5O>
this.nPos = nPos; <u2}i<#
oSavedFile.seek(nPos); NU0g07"
} F]<Xv"
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public synchronized int write(byte[] b,int nStart,int nLen) t2)rUWg
{ ,N)/w1?I
int n = -1; &G-!qxe
try{ /HaHH.e
oSavedFile.write(b,nStart,nLen); xoN3
n = nLen; <*qnY7c&N;
} #?S^kM-0
catch(IOException e) 6ZP"p<xX
{ Q637N|01
e.printStackTrace (); `G}TG(
} `7r@a
maNl^i
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return n; sc}~8T
} Sn|BlXrey
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X"fb;sGT
} 5;YMqUkw
Ck)*&
H*r)Z90
/* 4GX-ma,
**SiteInfoBean.java B\o Mn
*/ C)`Fv=]R
package NetFox; 85LAYaw
MB~=f[cUnd
A|<jX}
public class SiteInfoBean { C@'h<[v`1v
N u<_}
o%IA}e7PAa
private String sSiteURL; //Site's URL {y_98N
private String sFilePath; //Saved File's Path )!P)U(*v
private String sFileName; //Saved File's Name :qd`zG3
private int nSplitter; //Count of Splited Downloading File JPoN&BTCj
~=uWD&5B4
,Vt/(x-
public SiteInfoBean() K/|Z$4S
{//nSplitter的缺省值为5 x$6^R q>2
//default value of nSplitter is 5 vzim<;i
this("","","",5); E2Q[ZoVS
} !1$])VQWI
~Vr.J}]J
)p<ExMIxd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~?K~L~f5
{ 0.8 2kl
sSiteURL= sURL; }&wUr>=
sFilePath = sPath; &E.^jR~*
sFileName = sName; ewctkI$,5
this.nSplitter = nSpiltter; +JjW_Rl?=V
n[lJLm^(_C
^\4h<M
} z=q3Zo
iO|se:LY<
iOW#>66d
public String getSSiteURL() Ab{ K<:l
{ 9_Be0xgJ3^
return sSiteURL; 2AT5
} H|3:6x
Uq^#riq
zh8nc%X{
public void setSSiteURL(String value) [YlKR'_
{ [XEkz#{
sSiteURL = value; ;DFSzbF`
} 21K>`d\
`4=^cyt+
1_PoqD!q
public String getSFilePath() &,{fw@#)_
{ <G|(|E1
return sFilePath; fF7bBE)L/|
} `d5%.N
RI(DXWM|h
9]f!'d!5
public void setSFilePath(String value) tX_R_]v3
{ a7r%X -
sFilePath = value; D1zBsi94D
} p@xf^[50k
_m5uDF?[
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public String getSFileName() Enum/O5
{ %4et&zRC
return sFileName; J^SdH&%Z
} J;.wXS_U8
4|riKo)
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public void setSFileName(String value) /Z'L^L%R
{ "{@A5A
sFileName = value; 9K{%vK
} 47+&L
JtYP E?
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public int getNSplitter() )dbB=OZ
{ GpY"fc%
return nSplitter; Pg,b-W?n*
} 6Ypc`
E~Sb
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public void setNSplitter(int nCount) /uPcXq:L~
{ 8!O5quEc
nSplitter = nCount; uwzvbgup?
} }vxw*8d?
} ~zCEpU|@N
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{.?ZHy\Rk
/* *H"B _3<n
**Utility.java -]/I73!b
*/ #lmB AL~3
package NetFox; >`Y.+4mE
^Cu\VV
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public class Utility { IUE~_7
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-+(jq>t
public Utility() [#-b8Cu
{ @L<*9sLWh
7Ri46Tkt
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} .k,1f*%
RDW8]=uM
//线程睡眠 )97SnCkal
public static void sleep(int nSecond) `eE&5.
{ Y-kt.X/Z-
try{ Zn&, t &z
Thread.sleep(nSecond); Sg&UagBj
} ^o^H3m
catch(Exception e) >80;8\
{ HW3 }uP\c
e.printStackTrace (); )j9SGLo
} hL/)|N~
} xSktg]u Se
m+`fn;*
//日志 w~(1%p/
public static void log(String sMsg) .L9j>iP9 *
{ 7mI:|G
System.err.println(sMsg); D^yRaP*|7
} QS%%^+E2
nygbt<;?
K&vF0*gN3
public static void log(int sMsg) R<\F:9
{ RN$1bxY
System.err.println(sMsg); d/PiiiFf,
} x'+T/zw
} |jI#"LbF
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mw_~*Nc'9
/* 5's87Z;6
**TestMethod.java a|%J=k>>
*/ 9>l*lCA
package NetFox; Ov5"
+ln9c
^V?<K.F
public class TestMethod { ^8 zR
rf $QxJ
o)Iff)m$
public TestMethod() Li!Vx1p;u.
{ ///xx/weblogic60b2_win.exe )m`<H>[Eb=
try{ Rn}l6kbM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gp5_Z-me
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C"6?bg5N
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^N7e76VwR
fileFetch.start(); AP68V
} x.7]/)
catch(Exception e){e.printStackTrace ();} ;XF:\<+
cJ{ Nh;"
sx7eC
} &ib5*4!
,5i`-OI
W#^2#sjO
public static void main(String[] args) 0t Fkd
{ dCE0$3'5
new TestMethod(); < vL,*.zd
} 1;C+$
} =Q+;=-1
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