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)); ;0Tx-8l
} uLV#SQ=bZN
for(int i=0;i<nEndPos.length-1;i++) `x*Pof!Io
{ [TmIVQ!B
nEndPos = nStartPos[i+1]; d$1@4r
} ,5h)x"s
nEndPos[nEndPos.length-1] = nFileLength; I`!<9OTBj
} DW[N|-L
} F'21jy&
BI%$c~wS
<J`0
//启动子线程 $|@ (
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tVN
for(int i=0;i<nStartPos.length;i++) EFM5,gB.m
{ Y^wW2-,m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {ttysQ-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yd d7I&$
nStartPos,nEndPos,i); =c\>(2D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gi1^3R[
fileSplitterFetch.start(); 8<QdMkI
} Hquc o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "y}--
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b0Ps5G\ u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )6Fok3u
nEndPos = " + nFileLength); _uy44;zq
// fileSplitterFetch[nPos.length-1].start(); V2wb%;q
Po^?QVJ7
ig/xv
//等待子线程结束 )"7iJb<E
//int count = 0; UM"- nZ>[
//是否结束while循环 i9,geQ7d
boolean breakWhile = false; 1~NT.tY
qm/22:&v5
)vE~'W
while(!bStop) t.i 8 2Q
{ EM(gmWHij
write_nPos(); tEvut=k'
Utility.sleep(500); u04kF^
breakWhile = true; 'c9]&B
G[uK-U
nAsh:6${
for(int i=0;i<nStartPos.length;i++) <L8'!q}
{ TNe l/
if(!fileSplitterFetch.bDownOver) P@V0Mi),
{ rZ}:Z'`
breakWhile = false; kTOzSiq
break; y51e%n$
} NJWA3zz
} I-]?"Q7Jz
if(breakWhile) .ypL=~Rp
break; ^@s1Z7
Ot_]3:`J~
6]WAUK%h
//count++; z!ZtzD]cb
//if(count>4) h+g_rvIG*
// siteStop(); N/"{.3{W
} 84& $^lNV
|4;Fd9q^m
,~N/- 5
System.err.println("文件下载结束！"); IL#"~D?
} wDal5GJp
catch(Exception e){e.printStackTrace ();} }HYbS8'
} 2lH&
3Ei#q+7
BLQ6A<
//获得文件长度 P64PPbP
public long getFileSize() >* f-Wde
{ pP&7rRhw
int nFileLength = -1; O:;w3u7;u
try{ c_$=-Khk
URL url = new URL(siteInfoBean.getSSiteURL()); ;PF<y9M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &N^9JxN?8
httpConnection.setRequestProperty("User-Agent","NetFox"); aFX=C>M
UNu#(nP
dVtG/0
int responseCode=httpConnection.getResponseCode(); BUDi&|,
if(responseCode>=400) *5C7d*'
{ g[' ^L+hd
processErrorCode(responseCode); qZ}^;)a^
return -2; //-2 represent access is error vxBgGl
} C!<Ou6}!b
H(ARw'M
)4e.k$X^
String sHeader; _YhES-Ff
l`lk-nb
= SMXDaH
for(int i=1;;i++) cKca;SNql1
{ G:<aB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #4<SAgq
//Utility.log(in.readLine()); *SJ_z(CZm
sHeader=httpConnection.getHeaderFieldKey(i); :'X&bn
if(sHeader!=null) >C>.\
{ ?=Z?6fw
if(sHeader.equals("Content-Length")) C`hU]
{ ~d.Y&b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _aSxc)?
break; K<3A1'_
} X]TG<r
} )hsgC'H{~]
else Ko<:Z)PS
break; w3ResQ
} EeE7#$l
} D0-3eV-
catch(IOException e){e.printStackTrace ();} z#wkiCRYm
catch(Exception e){e.printStackTrace ();} T4Uev*A
<44G]eb
Cv.C;H
Utility.log(nFileLength); lfow1WRF
*w`sM%]Rq
Z"xvh81P
return nFileLength; 2*& ^v
} vm8eZG|
?(1y
rH Lm\3
//保存下载信息（文件指针位置） 6xx ?A>:
private void write_nPos() 6Pl<'3&
{ MAR'y8I
try{ Gx/Oi)&/
output = new DataOutputStream(new FileOutputStream(tmpFile)); >y7?-*0
output.writeInt(nStartPos.length); ~,Zc%s~|
for(int i=0;i<nStartPos.length;i++) +Mb.:_7'
{ dFB]~QEK
// output.writeLong(nPos); GR_-9}jQP
output.writeLong(fileSplitterFetch.nStartPos); `4J$Et%S
output.writeLong(fileSplitterFetch.nEndPos); lukB8
} m=:9+z
output.close(); p?OoC
} Dw.J2>uj
catch(IOException e){e.printStackTrace ();} k1~&x$G
catch(Exception e){e.printStackTrace ();} e#8Q L
} H/ HMm{4
NH4#
IHac:=*Q
//读取保存的下载信息（文件指针位置） rglXs
private void read_nPos() ~q.F<6O
{ p8O2Z?\
try{ (y~TL*B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mO7]9p
int nCount = input.readInt(); +~$ ]}%
nStartPos = new long[nCount]; !wVM= z^G
nEndPos = new long[nCount]; sY&IquK^
for(int i=0;i<nStartPos.length;i++) j</: WRA`]
{ Wqw1J=]
nStartPos = input.readLong(); *i%.;Z"
nEndPos = input.readLong(); %5n_ p^xp
} Xl#ggub?
input.close(); E{`fF8]K
} 45c$nuZ
catch(IOException e){e.printStackTrace ();} *]) `z8Ox
catch(Exception e){e.printStackTrace ();} ]h+j)J}[A
} R 'zWYQ
FcU SE
uw_Y\F-$
private void processErrorCode(int nErrorCode) R&k<AZ
{ 8OU\V5i[,q
System.err.println("Error Code : " + nErrorCode); 8Fu(Ft^9
} "<1{9
YjKxb9
}&J q}j
//停止文件下载 :crW9+
public void siteStop() 0'C1YvF
{ dR,fXQm
bStop = true; 29.h91
for(int i=0;i<nStartPos.length;i++) ?k{?GtSs
fileSplitterFetch.splitterStop(); q>+k@>bk@
JPw.8|V)y
]{@-HTt
} ( Erc3Ac8
} Kw ]=
//负责部分文件的抓取 3F2w-+L
**FileSplitterFetch.java pl?`8@dI
*/ ?CPahU
package NetFox; bROLOf4S
9W2Vo [(
5U$0F$BBp
import java.io.*; '\iCP1>+S
import java.net.*; )3EY;
w<(pl%
rg!r[1c
public class FileSplitterFetch extends Thread { rjYJs*#
0x@ mZ
OQJ6e:BGt
String sURL; //File URL q@8*Xa>
long nStartPos; //File Snippet Start Position jQB9j
long nEndPos; //File Snippet End Position Tyx_/pJT
int nThreadID; //Thread's ID /82b S|
boolean bDownOver = false; //Downing is over s.C_Zf~3
boolean bStop = false; //Stop identical &V/MmmT
FileAccessI fileAccessI = null; //File Access interface b8 likP"T
M .mfw#*
t'ql[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eeB{c.#
{ uKHxe~
this.sURL = sURL; _w+Qy.
this.nStartPos = nStart; cVF"!.
this.nEndPos = nEnd; 3 Za}b|
nThreadID = id; AoxA+.O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U>N1Od4vTO
} m9rp8r*e
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,k3FRes3
public void run() ISvpQ 3{)s
{ S<Xf>-8w
while(nStartPos < nEndPos && !bStop) 4^:=xL
{ "4{r6[dn
g}c~:p
aPL+=58r
try{ vEJbA
URL url = new URL(sURL); Q*Pq{]0K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H/M@t\$Dc
httpConnection.setRequestProperty("User-Agent","NetFox"); cbTm'}R(G
String sProperty = "bytes="+nStartPos+"-"; PdWx|y{%
httpConnection.setRequestProperty("RANGE",sProperty); 5=ryDrx
Utility.log(sProperty); 6=Otq=WH
_oeS Uzq.
gg2(5FPP
InputStream input = httpConnection.getInputStream(); `;egv*!P
//logResponseHead(httpConnection); 3^yK!-Wp(
Nj/ x. X
jmZI7?<z
byte[] b = new byte[1024]; utV_W&
int nRead; TM%%O :3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) + {'.7#
{ uwGc@xOgg,
nStartPos += fileAccessI.write(b,0,nRead); zdam^o
//if(nThreadID == 1) Zj'9rXhrM1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m)v&v6
} 'm$L Ij?@
DN6Mo<H
p4Z(^+Aa
Utility.log("Thread " + nThreadID + " is over!"); l.M0`Cn-%
bDownOver = true; Iu=(qU
//nPos = fileAccessI.write (b,0,nRead); f3y=Wxk[
} sRb9`u=)
catch(Exception e){e.printStackTrace ();} }Zp,+U*"
} |2A:eI8 ^
} SOIN']L|V[
do'GlU oMC
'LDQgC*%
//打印回应的头信息 \s\?l(ooq"
public void logResponseHead(HttpURLConnection con) wUJcmM;
{ P]C<U aW'!
for(int i=1;;i++) G' 1'/
{ x]j W<A
String header=con.getHeaderFieldKey(i); UJ2U1H54h
if(header!=null) xyXa .
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4^<?Wq~
Utility.log(header+" : "+con.getHeaderField(header)); n+M<\
else 6ik$B
break; '~ 47)fN
} .T`%tJ-Em
} <1TAw.
<F'\lA9
J<lW<:!3]
public void splitterStop() JW&gJASGC
{ gjlx~.0d
bStop = true; !5!<C,U
} {{!-Gr
Q+{n-? :
Nz-&MS
} |DwZ{(R"W
0> \sQ,T
eyxW 0}[
/* #O&8A
**FileAccess.java Pg{J{gn
*//文件访问(定位，写) m]&SNz=
package NetFox; t6t!t*jO
import java.io.*; 7d\QB(~
#\ErY3k6&
lU]nd[x
public class FileAccessI implements Serializable{ 7t3!)a|lI
+ZX{>:vo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 # f\rt
RandomAccessFile oSavedFile; 8zb/xP>
long nPos; n=q76W\
0n'_{\yz
cZ3v=ke^
public FileAccessI() throws IOException _yT Ed"$
{ '5tCz9}Y
this("",0); ?V=CB,^
} h2QmQ>y"
4^d?D!j
0*v2y*2V
public FileAccessI(String sName,long nPos) throws IOException XK vi=0B
{ cz$2R
oSavedFile = new RandomAccessFile(sName,"rw"); /mZE/>&~,
this.nPos = nPos; Zwx%7l;C
oSavedFile.seek(nPos); !5N.B|Nt
} 5lum$5
|':{lH6+1
Y4YJJYvD
public synchronized int write(byte[] b,int nStart,int nLen) .RL=xb|[
{ {4PwLCy
int n = -1; 9tnD=A<PS
try{ z(~_AN M4,
oSavedFile.write(b,nStart,nLen); u1.BN>G
n = nLen; ~>XxGjxe
} eJX#@`K
catch(IOException e) ji="DYtL
{ R@2X3s:
e.printStackTrace (); A=>u 1h69
} D m9sL!
Xwtqi@zlE
h yIV.W/
return n; [-x7_=E#
} k;W XB|k
`H+lPM66
4&iCht =
} Z30A{6}
"wc<B4"
")25 qZae
/* S|}L&A
**SiteInfoBean.java AOx[
*/ "Yy n/
package NetFox; t`QENXA}
Xnh8e
##ANrG l
public class SiteInfoBean { i@'dH3-kO
P93@;{c(
6H|S;K+
private String sSiteURL; //Site's URL z?//rXuO
private String sFilePath; //Saved File's Path UCWBYC+
private String sFileName; //Saved File's Name Ir]\|t
private int nSplitter; //Count of Splited Downloading File zW nR6*\
?h2}#wg
`y0FY&y=
public SiteInfoBean() zBH2@d3W
{//nSplitter的缺省值为5 WEpoBP CL
//default value of nSplitter is 5 bPMhfK2 %
this("","","",5); wyG;8I
} yDS4h(^
nRY5xRvK
:hA#m[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E\$W_Lmr
{ Q@HV- (A
sSiteURL= sURL; Y\tui+?J
sFilePath = sPath; !&\INl-Z
sFileName = sName; tnIX:6
this.nSplitter = nSpiltter; D`AsRd
.e5Mnd%$M
j|Q-*]V
} C7?/%7{
et+0FF ,
P|> ~_$W
public String getSSiteURL() ?fS9J
{ PaN"sf
return sSiteURL; NuI9iU
} QCJM&
oXS}IL og'
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public void setSSiteURL(String value) d!{r v
{ q'11^V!0
sSiteURL = value; B1Oq!k
} |'2d_vR
BORA(,
LHmZxi?
public String getSFilePath() .8|X
{ SY8C4vb'h
return sFilePath; B\n[.(].r
} F5#YOck&,
H:\k}*w
"h ^Z
public void setSFilePath(String value) aN=B]{!
{ Er[A X.3
sFilePath = value; J-4:H gx
} 'W#D(l9nI
1nOCQ\$l
bN88ua}k{
public String getSFileName() |Ds=)S" K
{ A(N4N
return sFileName; 1&$ nVQ
} XZwK6F)L
c"xK`%e
\(T/O~b2
public void setSFileName(String value) ,=N.FS
{ k+4#!.HX^
sFileName = value; Cls%M5MH
} 07$o;W@
'3H_wd
[8*)8jP3
public int getNSplitter() Xx(T">]vJ
{ 3BLqCZ
return nSplitter; M@ZI\
} KG5>]_GH
]s748+
]9,;K;1<
public void setNSplitter(int nCount) FGQzoS
{ v9UD%@tZ
nSplitter = nCount; #o2[hibq
} Q5_o/wk
} o`RKXfCq
o? $.fhD
6`-jPR
/* JMM W
**Utility.java [fIg{Q
*/ c0fo7|
package NetFox; I2^8pTLh
<^uBoKB/f
sT' 5%4
public class Utility { ]0\MmAJRn
O| hpXkV
+'w3 =2Bo
public Utility() r"R#@V\'1b
{ cFWc<55aX6
FsryEHz
188*XCtjQ9
} 5PnDN\
k;L6R!V
//线程睡眠 :,I:usW"
public static void sleep(int nSecond) E+JqWR5
{ V2G6Kw9gt
try{ ]$_NyAoBb
Thread.sleep(nSecond); kSh( u
} ?F;8Pa/
catch(Exception e) !v0LBe4
{ /FJu)H..U
e.printStackTrace (); })?GzblI&
} = 9]~yt
} B93+BwN>95
vZoaT|3 G]
//日志 eGHaY4|
public static void log(String sMsg) Ub!(H^zu
{ O1mKe%'|
System.err.println(sMsg); ,4oo=&
} ?K\axf>F
ZQ0F$J)2~
:08,JL{
public static void log(int sMsg) ?S$P9^ii'
{ xF44M]i
System.err.println(sMsg); 8ITdSg
} '6Q=#:mc\
} C73kJa
?1eK#Z.
Ue~CwFOc
/* >oe]$r
**TestMethod.java ^a1^\X.~
*/ :[!j?)%>
package NetFox; abLnI =W`
uU25iDn
Z/;aT -N
public class TestMethod { I(0~n,=j
iW /}#
9p2&)kb6
public TestMethod() cjIh}:|'
{ ///xx/weblogic60b2_win.exe {,~3.5u
try{ 6f*CvW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); & 9 ?\b7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7x4PaX(
SiteFileFetch fileFetch = new SiteFileFetch(bean); qeZ? 7#Gf
fileFetch.start(); KMjhZap%
} <HVt V9R
catch(Exception e){e.printStackTrace ();} "!%l/_p?
YVanW
Gk /fBs
} :A'y+MnK<
)/?$3h;
b`O'1r\Y;
public static void main(String[] args) ={wcfhUl+
{ R[x_j
new TestMethod(); }d}Ke_Q0
} 5S--'=fu+
} ?oHpFlj
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