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)); a!MhxM5
} L8K=Q
for(int i=0;i<nEndPos.length-1;i++) 1:<=zqh0
{ 4`F(RweGx
nEndPos = nStartPos[i+1]; >$=-0?.
} ?Xm!;sS0
nEndPos[nEndPos.length-1] = nFileLength; 8H4"mxO
} 1iq,Gd-G.
} <7HVkAa
J&4QI( b.
u.( WW(/N
//启动子线程 QFOmnbJg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wD|,G!8E2
for(int i=0;i<nStartPos.length;i++) #L}YZ
{ uGm~ Oo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rQ|^HNj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kCkSu-
nStartPos,nEndPos,i); _{CMWo"l
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |cpBoU
fileSplitterFetch.start(); qd*3| O^
} '< ]:su+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7.fpGzUM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WPVur{?<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _jK
nEndPos = " + nFileLength); dR"H,$UH
// fileSplitterFetch[nPos.length-1].start(); 5b X*8H D
:TU;%@7
%M{qr!?uj
//等待子线程结束 Zw+VcZz3
//int count = 0; jR-`ee}y2
//是否结束while循环 c"BFkw
boolean breakWhile = false; OgJd^
su]CaHU
tydD~a
while(!bStop) GOJ*>GpS
{ cU8Rm\?
write_nPos(); BrYU*aPW;
Utility.sleep(500); ,4oYKJ$+h
breakWhile = true; FQdz":5
7%?2>t3~
DSGtt/n
for(int i=0;i<nStartPos.length;i++) WAPN,WuW
{ :.kc1_veYS
if(!fileSplitterFetch.bDownOver) w~J 7|8Y
{ ;h[p "
breakWhile = false; ;V(- ;O
break; 8wGq:@#=
} mG4myQ?$
} XMb]&VvH
if(breakWhile) :uhU<H<,f
break; 5wM*(H^c[
juQ&v>9W)
IC&xL9
//count++; _DPWp,k<~
//if(count>4) ylm*a74-X
// siteStop(); i oX [g
} Y<('G5A
JmDi{B?
pvL)BD
System.err.println("文件下载结束！"); E$5)]<p! <
} Jy&O4g/'5
catch(Exception e){e.printStackTrace ();} [{.e1s<EK
} Q 6djfEN>
OiI[w8
#<ppiu$
//获得文件长度 r|$@Wsb?#
public long getFileSize() ~(E.$y7P
{ }{>)2S
int nFileLength = -1; j8p</gd
try{ nn>1OO
URL url = new URL(siteInfoBean.getSSiteURL()); ""cnZZ5)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4yhan/zA
httpConnection.setRequestProperty("User-Agent","NetFox"); ^LfN6{
H/8H`9S$
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int responseCode=httpConnection.getResponseCode(); ACQc 0:q
if(responseCode>=400) 8S2sNpLi-g
{ *`~ woF
processErrorCode(responseCode); dQUZ11
return -2; //-2 represent access is error X0<qG
} P:GAJ->;]>
*^j'G^n
R`}C/'Ty
String sHeader; 7_Yxz$m
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6&8([J
for(int i=1;;i++) yuyI)ebC
{ l*^J}oY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W[trsFP1?
//Utility.log(in.readLine()); @tQu3Rq@
sHeader=httpConnection.getHeaderFieldKey(i); 3vx5dUgl,
if(sHeader!=null) )?35!s6
{ AF ,*bb
if(sHeader.equals("Content-Length")) HUF],[N
{ Tb~|p_;o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (,Zy2wr=
break; y/}[S@4uB
} zrt\]h+
} o+UCu`7e
else +O`3eP`u
break; <a9<rF =r
} L%G/%*7;c
} VyQ@. Lm
catch(IOException e){e.printStackTrace ();} H CKD0xx
catch(Exception e){e.printStackTrace ();} ;Du+C%
? yL3XB>
T(LqR?xOo
Utility.log(nFileLength); !|!k9~v!
^PwZP;On
#_]/Mr1
return nFileLength; }yQ&[Mt
} ~s.~X5
Yj%hgb:)
ra87~kj<
//保存下载信息（文件指针位置） a]0B{
private void write_nPos() @.IGOh
{ w>-@h>Ln
try{ U^qQ((ek
output = new DataOutputStream(new FileOutputStream(tmpFile)); p mv6m
output.writeInt(nStartPos.length); 0,1x- yD
for(int i=0;i<nStartPos.length;i++) ZJL8"(/R
{ _v~c3y).
// output.writeLong(nPos); +ucj>g1(#
output.writeLong(fileSplitterFetch.nStartPos); m\9R;$\
output.writeLong(fileSplitterFetch.nEndPos); yV{&x
} G]Rb{v,r
output.close(); _+c' z
} gcS?r :
catch(IOException e){e.printStackTrace ();} x`7Ch3`4}
catch(Exception e){e.printStackTrace ();} zKRt\;PW
} 2~`lvx
@9,=|kxK
t:MeSO
//读取保存的下载信息（文件指针位置） R/!lDv!
private void read_nPos() g]kM7,/M
{ &j}08aK%
try{ 9;W2zcN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *\#/4_yB}
int nCount = input.readInt(); -cDS+*[
nStartPos = new long[nCount]; z{wW6sgPr
nEndPos = new long[nCount]; .h({P#QT
for(int i=0;i<nStartPos.length;i++) Uc>kiWW
{ !VLk|6mn
nStartPos = input.readLong(); :/rl \woA>
nEndPos = input.readLong(); Y-Iu&H+\
} ALcin))+B
input.close(); Q{+*F8%8V<
} 2@TgeV0Y[
catch(IOException e){e.printStackTrace ();} #}M\ J0QG
catch(Exception e){e.printStackTrace ();} IP?15l w
} kSW=DE|#}
L{pz)')I
F~bDA~
private void processErrorCode(int nErrorCode) v,T:V#f^
{ " V[=U13
System.err.println("Error Code : " + nErrorCode); 9Hu;CKs
} }I}/e v
.[8! E_
/,C;fT<R
//停止文件下载 {oXU)9vj
public void siteStop() ^$FNu~|K
{ H1bHQB
bStop = true; _ MsO2A
for(int i=0;i<nStartPos.length;i++) 2/WtOQIB
fileSplitterFetch.splitterStop(); PpXzWWU":
mS$9D{
[zC1LTXe
} CdEQiu
} P}`|8b1W
//负责部分文件的抓取 PL/g@a^tY
**FileSplitterFetch.java HZASIsl
*/ >-&B#Z^,
package NetFox; 8k( zU>^
t4;eabZK
lpq)vKM}^
import java.io.*; `Wl_yC_*G;
import java.net.*; /EIQMZuYp
Ob~7w[n3
]QU 9|1
public class FileSplitterFetch extends Thread { `p!&>,lrk
MV{\:l}y
H^Mfj!S
String sURL; //File URL 5VS};&f
long nStartPos; //File Snippet Start Position Ie<H4G5Vh
long nEndPos; //File Snippet End Position gg0rkg
int nThreadID; //Thread's ID -gQtw% `x
boolean bDownOver = false; //Downing is over T}}T`Ce
boolean bStop = false; //Stop identical kk`K)PESi
FileAccessI fileAccessI = null; //File Access interface bIXudE[8zq
<<=.;`(/v
8AjQPDn+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]KQv]'
{ 9T\uOaC"
this.sURL = sURL; @$Xl*WT7
this.nStartPos = nStart; VGYx(
this.nEndPos = nEnd; k~0#Iy_{M
nThreadID = id; r*q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eS`ZC!W
} R7o'V* d
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public void run() CL|d>
{ "[QQ(]={
while(nStartPos < nEndPos && !bStop) &%UZ"CcA
{ <~ Dq8If
?v z[Zi
a Xn:hn~O
try{ AqA.,;G
URL url = new URL(sURL); pqCp>BO?O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xA'RO-a}h
httpConnection.setRequestProperty("User-Agent","NetFox"); :' =le*h
String sProperty = "bytes="+nStartPos+"-"; dEhFuNO<2
httpConnection.setRequestProperty("RANGE",sProperty); 0$qK: ze
Utility.log(sProperty); dfA2G<Uc
_v#Vf*#
Zt"#'1
InputStream input = httpConnection.getInputStream(); SHc?C&^S
//logResponseHead(httpConnection); :hBLi99 o
)krBjF.$
B:>>D/O
byte[] b = new byte[1024]; ?NVX# t'
int nRead; qEvbKy}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u?F^gIw
{ O:]e4r,'
nStartPos += fileAccessI.write(b,0,nRead); | |u
//if(nThreadID == 1) %ws@t"aER
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BvLC%
} ^, &'
/HE{8b7n3F
~eZ]LW])
Utility.log("Thread " + nThreadID + " is over!"); Z,~PW#8<&
bDownOver = true; h+c9FN
//nPos = fileAccessI.write (b,0,nRead); i*]$_\yl"
} dEI]|i r
catch(Exception e){e.printStackTrace ();} U>i}C_7g
} /u&7!>,
} 0;L.h|R T(
H -K%F_#
[ KDNKK
//打印回应的头信息 Z?<&@YQS
public void logResponseHead(HttpURLConnection con) G@3Jw[t
{ JLbmh1'
for(int i=1;;i++) YfstE3BV
{ a)8;P7
String header=con.getHeaderFieldKey(i); 0<XxR6w
if(header!=null) ei82pLM z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]&?8l:3-G
Utility.log(header+" : "+con.getHeaderField(header)); I&%KOe0
else lt("yqBu
break; ATWa/"l(H-
} nh]HEG0CZJ
} `qV*R 2
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l[6lXR&|
public void splitterStop() 0m,q3
{ d3]<'B:nb
bStop = true; >rYkVlv
} P9o=G=i
>x1yFwX}-f
7fC:'1]G
} _7;D0l
pupt__NZ)n
wu.>'v?y
/* z+K1[1SM
**FileAccess.java KRM:h`+-.-
*//文件访问(定位，写) n#5S-z1KNw
package NetFox; F@b=S0}K
import java.io.*; n}dLfg*
} 4ZWAzH
cR=o!2O
public class FileAccessI implements Serializable{ tZY6{,K%4
;YZ'd"0v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )~CNh5z6Y
RandomAccessFile oSavedFile; RB9ZaL\
long nPos; $>zqCi2tB<
N<O<wtXIj
iB}*<~`.Eg
public FileAccessI() throws IOException RBLOc$2
{ [ut[W9
this("",0); txiX1o!/L
} O Cnra
UZ1Au;(|
-' =?Hs.
public FileAccessI(String sName,long nPos) throws IOException _`.Q7
{ !tSh9L;<O
oSavedFile = new RandomAccessFile(sName,"rw"); d+nxvh?I8
this.nPos = nPos; c=D~hzN
oSavedFile.seek(nPos); zJ_y"bt
} SPp|/ [i7
_h I81Lzq
LvMA('4
public synchronized int write(byte[] b,int nStart,int nLen) pV`/6 }
{ '?6j.ms M
int n = -1; (v&iXD5t
try{ (3Z;c_N
oSavedFile.write(b,nStart,nLen); !xU[BCbfYV
n = nLen; lV9
} Svdmg D!
catch(IOException e) }1 j'
{ =&)R2pLs*
e.printStackTrace (); 7M~/[f7Z{
} pM~-o?
|'j,|^<
}nptmc
return n; QabLMq@n`
} wlEK"kKU
>[ g=G
Os*s{2OvO
} qYQ vjp
pq:[`
rl x6a@MiD
/* QZ+G2$
**SiteInfoBean.java /I:&P Pff
*/ YRCOh:W*
package NetFox; RN$>!b/
6m@B.+1
Ed+jSO0
public class SiteInfoBean { lx7]rkWo|a
e|q~t {=9S
8~F?%!X
private String sSiteURL; //Site's URL %LuA:{EVD
private String sFilePath; //Saved File's Path M^lP`=sSv
private String sFileName; //Saved File's Name 6`X}Z'4.Ox
private int nSplitter; //Count of Splited Downloading File i v.G
tns4e\
f@k.4aS
public SiteInfoBean() !="8ok+
{//nSplitter的缺省值为5 y&V'GhW!dd
//default value of nSplitter is 5 P26"z))~d
this("","","",5); tO?-@Qf/9<
} i1K$~
f`iDF+h<6
!JBj%|!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u'^kpr`y
{ 'hFL`F*
sSiteURL= sURL; ?<T=g
sFilePath = sPath; /!N=@z)
sFileName = sName; cgO<%_l3`
this.nSplitter = nSpiltter; Y ` Z,52
8T[<&<^-
Cu_-QE
} n(i/jW~0w
rM? J40&.
M@Ti$=
public String getSSiteURL() ~[f`oC
{ Er -rm
return sSiteURL; 7* [
} IZGRQmi"
//RD$e?h~
t*)!BZ
public void setSSiteURL(String value) y.-Kqa~
{ c|K:oi,z
sSiteURL = value; "xnULQK
} Xkk 8#Y":
E^0a; |B[
=\mJ5v"hA
public String getSFilePath() TM|PwY
{ ?<S fhjU
return sFilePath; [Zzztn+
} SM1L^M3)
qlnA7cK!
O<ybiPR
public void setSFilePath(String value) } 7ND]y48
{ c^&4m[?C[u
sFilePath = value; ~SmFDg$/m
} xu{VU^'Y
fWb+08}C
^Pah\p4bj
public String getSFileName() +~=j3U
{ 4P"XT
return sFileName; itg"dGDk
} C XNYWx
-wf>N:
MTq/
public void setSFileName(String value) rU(-R@["
{ l%p,m[
sFileName = value; #N%j9
} EB@rIvUi,
KT7R0v
.*X=[" F
public int getNSplitter() c]i;0j? Dl
{ IkG;j+=
return nSplitter; Vol}wc
} ,`YIcrya:
Z$B%V t
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public void setNSplitter(int nCount) +1@'2w{
{ ;.b^&h
nSplitter = nCount; &aa3BgxyE
} -%Rbd0gVH\
} awjAv8tPO!
}Oqt=Wm
kB%.i%9\\
/* hc|#JS2H@y
**Utility.java fn.;C
*/ ~N7;. 3 7
package NetFox; AX{7].)F
U9*< dR
&0H_W xKeB
public class Utility { ;*ni%|K
Wyow MFp
S<-5<Pg
public Utility() 9}L2$^#,NA
{ 3}fhU{-c
G}LV"0?
b|;h$otC
} PHUeN]s#
A;*<
//线程睡眠 ~Nf|,{[(5
public static void sleep(int nSecond) IYHNN
{ 2+b}FVOe\
try{ >>"@0tO
Thread.sleep(nSecond); L"NfOST3'R
} >yVp1Se
catch(Exception e) cYXL3)p*Q
{ bUds E1f
e.printStackTrace (); B=7maYeU
} cV_-Bcb
} wAJ=rRI
)]4=anJu@|
//日志 u^#e7u
public static void log(String sMsg) ZHlHnUo
{ ~B?Wg!
System.err.println(sMsg); 2$`Y 4b3t
} zL3zvOhu}
K4+|K:e
71ab&V il
public static void log(int sMsg) b'z\|jY
{ XHOS"o$y
System.err.println(sMsg); lN0u1)'2
} 8R-;cBT
} 5uOz#hN
mdo$d-d&
4sW~7:vU
/* cMoJHC,!
**TestMethod.java -t>"s'kv
*/ ]0[ot$Da6
package NetFox; %iJ}H6m
ls7P$qq
^zS;/%
public class TestMethod { Bu+?N%CBi
L6;'V5Mg72
LGVy4D
public TestMethod() wZW\r!Us
{ ///xx/weblogic60b2_win.exe F?0Q AA
try{ ckv8QAm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [tElt4uG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >"|t*kS
SiteFileFetch fileFetch = new SiteFileFetch(bean); tmM; Z(9t
fileFetch.start(); Y>ATL
} 3-)}.8F
catch(Exception e){e.printStackTrace ();} uPxjW"M+
U0srwt97S
&\Lu}t7Ru
} ZLPj1L
c@)?V>oe
&%8IBT
public static void main(String[] args) }$r]\v
{ ;:+2.//
new TestMethod(); n}fV$qu
} yy&L&v'
} K5\l (BB
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