http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 6:ettdj
} _=GjJ~2n
for(int i=0;i<nEndPos.length-1;i++) $4nAb^/
{ : {p'U2
nEndPos = nStartPos[i+1]; d y HC8
} ,vR?iNd:q[
nEndPos[nEndPos.length-1] = nFileLength; v'W{+>.
} uuC ["Z
} X-c|jn7
XQ#K1Z
D.K""*ula
//启动子线程 v675C#l(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Eomfa:WL
for(int i=0;i<nStartPos.length;i++) XX8HSw!w
{ +>Wo:kp3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K-0=#6?y4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xz_WFLq4
nStartPos,nEndPos,i); ZL( j5E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \}Jznzx;
fileSplitterFetch.start(); !dLu($P
} 2J7|y\N,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U#jz5<r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @/z\p7e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h?mDtMCw2
nEndPos = " + nFileLength); :os8"
// fileSplitterFetch[nPos.length-1].start(); \P<aK$g
5Gz!Bf@!!
2S?7j[@%i`
//等待子线程结束 >,e^}K}C
//int count = 0; bA^uzE
//是否结束while循环 n{tc{LII/
boolean breakWhile = false; ,md_eGF
8q^}AT<C
dli(ckr
while(!bStop) (` *BZ_
{ 1'~Xn 4 f
write_nPos(); n1sYD6u<&
Utility.sleep(500); pbH!u+DF
breakWhile = true; jIol`WX
?qgQ)#6
a(gXvgrf[
for(int i=0;i<nStartPos.length;i++) 3s6obw$ki
{ TSB2]uH
if(!fileSplitterFetch.bDownOver) |Y7SP]/`gB
{ +:S`]
breakWhile = false; cOVj @z
break; yHeL&H
} J p'^!
} scg&"s
if(breakWhile) i2=- su
break; h^Wb<O`S
G+zhL6]F
Q:A#4Z
//count++; 2bt>t[0ad
//if(count>4) rzfLp
// siteStop(); L'+bVP{L
} Z-iU7 O
4MgN
%_(vSpk
System.err.println("文件下载结束！"); 6,>$Jzs)5E
} uNyU]@R<W
catch(Exception e){e.printStackTrace ();} _{[6hf4p
} 3#7V1
\Zj%eW!m
jPWONz(#
//获得文件长度 hb`9Vn\-E
public long getFileSize() \|PiQy*_?
{ Z@bgJL83
int nFileLength = -1; -CvmZ:n
try{ dbf<k%i6
URL url = new URL(siteInfoBean.getSSiteURL()); c8uaZvfW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]LvP)0=
httpConnection.setRequestProperty("User-Agent","NetFox"); jSI1tW8
V:\:[KcL^
4 &bmt
int responseCode=httpConnection.getResponseCode(); , $7-SN
if(responseCode>=400) NI?O
{ f_~T
processErrorCode(responseCode); dxeiN#(XT
return -2; //-2 represent access is error )D8op;Fn
} 8zK#./0\
_Ewh:IM-
1eI*.pt
String sHeader; ufXWK3~\
T`#nn|
v "l).G?
for(int i=1;;i++) GfONm6A
{ a\P:jgF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +XWTu!
//Utility.log(in.readLine()); ?_eLrz4>L^
sHeader=httpConnection.getHeaderFieldKey(i); FB6Lz5:Vf
if(sHeader!=null) <*5S7)]BP
{ wB)y@w4k
if(sHeader.equals("Content-Length")) ;[y( 14g
{ gj^)T_E_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F_@B ` ,
break; e{x>u(
} b|i4me@
} ~XR('}5D
else |lNp0b
break; 72l:[5ccR
} }a"=K%b<\
} A$2 ;Bf
catch(IOException e){e.printStackTrace ();} [UwQi!^-O
catch(Exception e){e.printStackTrace ();} $0V+<
d+DO}=]
@X/ 1`Mp
Utility.log(nFileLength); @b(@`yz.a
klKUX/g
@Ou H=<YN
return nFileLength; ]xRR/S4
} i!YfR]"}
?`+VWa[,e
\GEz.Vb
//保存下载信息（文件指针位置） :!Ci#[g
private void write_nPos() OU{c|O
{ uH\EV`@'
try{ `+w= p7ET
output = new DataOutputStream(new FileOutputStream(tmpFile)); lWRl
output.writeInt(nStartPos.length); U$2Em0HO}
for(int i=0;i<nStartPos.length;i++) ,7V?Kj
{ Do4hg $:40
// output.writeLong(nPos); kn:hxdZ
output.writeLong(fileSplitterFetch.nStartPos); NfDS6i.Fqp
output.writeLong(fileSplitterFetch.nEndPos); Zj[m
} .>W [
output.close(); 1uw1(iL+
} #M!u';bZ
catch(IOException e){e.printStackTrace ();} gdIk%m4
catch(Exception e){e.printStackTrace ();} q 4Pv\YO
} .]E(P
2S7BzZ/
JWHsTnB
//读取保存的下载信息（文件指针位置） w10~IP
private void read_nPos() syu/"KY^!
{ N[eLQe]q
try{ WWSycH ?[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H!Gw@u]E
int nCount = input.readInt(); $6m@gW]N
nStartPos = new long[nCount]; D2VYw<tEA
nEndPos = new long[nCount]; cn}15JHdR
for(int i=0;i<nStartPos.length;i++) }"+"nf5h
{ )VQ[}iT
nStartPos = input.readLong(); 'A|c\sy
nEndPos = input.readLong(); ou0TKE9 _
} +788aK,{#
input.close(); NK|U:p2H
} mh4 VQ9
catch(IOException e){e.printStackTrace ();} o|>=<l
catch(Exception e){e.printStackTrace ();} -`8@
} ?5't1219
!RJ@;S
9]N{8
private void processErrorCode(int nErrorCode) XR",.3LD
{ t{UVX%b
System.err.println("Error Code : " + nErrorCode); 4U\>TFO
} $cn8]*Z=
d7BpmM
O-[YU%K3?
//停止文件下载 Ak3^en
public void siteStop() F4~OsgZ'N
{ 3B;Gm<fJ9N
bStop = true; .WSn Y71
for(int i=0;i<nStartPos.length;i++) MMk9rBf
fileSplitterFetch.splitterStop(); @F8NN\
Pg.JI:>2Ku
(,sz.
} V}TPt6C2
} cFie;k
//负责部分文件的抓取 j)G%I y[`
**FileSplitterFetch.java m\*ca3$
*/ bv <^zuV
package NetFox; H,<CR9@(5d
Zz (qc5o,F
_*=4xmB.=
import java.io.*; ommW
import java.net.*; c1kV}-v
oeKl\cgFx
Q~"Lyy8
public class FileSplitterFetch extends Thread { /Q W^v;^
+)h# !/
zEQQ4)mA
String sURL; //File URL rhzI*nwOT
long nStartPos; //File Snippet Start Position N6kMl
long nEndPos; //File Snippet End Position O<wH+k[
int nThreadID; //Thread's ID xK0;saG#
boolean bDownOver = false; //Downing is over [Cd#<Te3
boolean bStop = false; //Stop identical o1 27? ^
FileAccessI fileAccessI = null; //File Access interface 8yYag[m8
qPi $kecx
&:C[ nq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Nq9pory^
{ u`B/9-K)y
this.sURL = sURL; c='W{47
this.nStartPos = nStart; Ib2&L
this.nEndPos = nEnd; Dd0yQgCu
nThreadID = id; b"@-9ke5I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nzxHd7NIZ
} %1cxZxGT
o9ys$vXt*
#2\M(5d
public void run() })!-
{ n9 bp0#K
while(nStartPos < nEndPos && !bStop) V@LBy1z
{ .rg "(I
L4+R8ojG
rv)Eg53Q
try{ r_ m|?U %
URL url = new URL(sURL); W@GU;Nr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ku57<kb
httpConnection.setRequestProperty("User-Agent","NetFox"); H[g i`{c
String sProperty = "bytes="+nStartPos+"-"; EQ"_kJ>81Y
httpConnection.setRequestProperty("RANGE",sProperty); rY&lx}
Utility.log(sProperty); ;E{@)X..|
qc'KQ5w7!
U4a8z<l$
InputStream input = httpConnection.getInputStream(); FME,W&_d
//logResponseHead(httpConnection); L#D)[v"
=.J>'9Q
~y Dl& S
byte[] b = new byte[1024]; |VE.khq#
int nRead; `{yD\qDyX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +|oLS_
{ .2P3 !KCL
nStartPos += fileAccessI.write(b,0,nRead); 7"eIZ
//if(nThreadID == 1) U1yspHiZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -hF!_);{
} rWJRoGk/
(.z0.0W
bQ?Vh@j(M
Utility.log("Thread " + nThreadID + " is over!"); @d5t%V\
bDownOver = true; b*Hk} !qH
//nPos = fileAccessI.write (b,0,nRead); b!QRD'31'j
} 7 mA3&<&q
catch(Exception e){e.printStackTrace ();} ~s?y[yy6i
} DjZTr}%q
} blG?("0!
KKg\n^
:[PA.Upi
//打印回应的头信息 hOqNZ66{
public void logResponseHead(HttpURLConnection con) -e51/lhpd
{ >_\]c-~<
for(int i=1;;i++) DDT]A<WUV
{ lS2`#l>
String header=con.getHeaderFieldKey(i); `LwZ(M-hI
if(header!=null) %0u5d$bq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); CJ3/8*;w
Utility.log(header+" : "+con.getHeaderField(header)); 8;UkZN"hy5
else X)TZ S
break; 8BY`~TZO$q
} /K,@{__JP
} |e+r~).4B
T/%k1Hsa4H
kDiR2K&
public void splitterStop() sBxCi~
{ )DW".c
bStop = true; *xeJ4h
} 0!c/4^
kmJ<AnK
tsB}'+!v#
} g]b%<DJ
21?>rezJ
rd(-2,$4
/* $0M7P5]N*G
**FileAccess.java |f}`uF
*//文件访问(定位，写) +miL naO~L
package NetFox; '7]9q#{su
import java.io.*; 5"x1Pln
obX2/
>^f]Lgp
public class FileAccessI implements Serializable{ wC<FF2T
85H*Xm?d#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zs-,Y@ZL
RandomAccessFile oSavedFile; cnDBT3$~Z
long nPos; naY#`xig
nrTCq~LO(
2Y}A9Veb
public FileAccessI() throws IOException esv<b>`R
{ `1 Tg8
this("",0); }V+&o\4
} M7gqoJM'Q
m}m|(;T
@<S'f<>g
public FileAccessI(String sName,long nPos) throws IOException %CrpUx
{ 61b<6r0o
oSavedFile = new RandomAccessFile(sName,"rw"); 'Te'wh=Y
this.nPos = nPos; |L)qH"Eo
oSavedFile.seek(nPos); ?`SBGN;
} 8?o{{ay
:y!{=[>M(
%A@U7gqc
public synchronized int write(byte[] b,int nStart,int nLen) %8"Aq
{ y$|OE%S
int n = -1; y=1(o3(
try{ ,ce$y4%(
oSavedFile.write(b,nStart,nLen); 7ws[Rp8
n = nLen; ;p(Doy)i
} BLo=@C%w5
catch(IOException e) "L)?dlb6T
{ W$R@Klz
e.printStackTrace (); {f>e~o
} ]"vpCL
nlx~yUXL4
d:n.Vp
return n; n*qn8Dq
} lHgmljn5u
_4t
k'd=|U;(FV
} T!H }^v
4V5h1/JPm
Nu%MXu+
/* sTYA
**SiteInfoBean.java 4p(\2?B%f
*/ u,Cf4H*xS
package NetFox; *2I@_b6&
/3 ;t &]
SDW!9jm>R
public class SiteInfoBean { @(e/Y/
iC<qWq|S_m
+r]2.
private String sSiteURL; //Site's URL vj<JjGP
private String sFilePath; //Saved File's Path ?7aeY5p
private String sFileName; //Saved File's Name WNV}@
private int nSplitter; //Count of Splited Downloading File AhSN'gWpbF
&;%LTF@I,
E"Y[k8-:2/
public SiteInfoBean() Ivc/g,
{//nSplitter的缺省值为5 sMWNzt
//default value of nSplitter is 5 y)+lU
this("","","",5); #6Fc-ysk:
} 140_WV?7
ygTc Y
]AB4w+6!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @avG*Mr^
{ n]WVT@
sSiteURL= sURL; Q2xzux~T
sFilePath = sPath; <825?W|
sFileName = sName; "?{=|%mf
this.nSplitter = nSpiltter; q!8aYw+c
Fpy-?U
*Ag,/Cm]
} |`ZW(}~
-Y/c]g
4Y}{?]>pu
public String getSSiteURL() Z[zRZ2'i5
{ MJI`1*(
return sSiteURL; xEqr3(
} HO9w"){d$
c`_[q{(^m
\zyvu7YA
public void setSSiteURL(String value) 45tQ$jr`1
{ j.7BoV
sSiteURL = value; QNgfvy
} nK9?|@S*'
o",J{
Ex$i8fO(
public String getSFilePath() 6Y&`mgMF'
{ J`d;I#R%c
return sFilePath; ._US8
} +I r
C7T}:V](q
me&'BQ
public void setSFilePath(String value) v<tr1cUT
{ 'o]8UD(
sFilePath = value; zP|^) h5
} Y4I;-&d's
58o'Q
jLv8K
public String getSFileName() *t,1(Gw|7q
{ ,\=,,1_
return sFileName; n]fMl:77
} wj<fi
w>h\643
cCbZ*
public void setSFileName(String value) BXB ZX@jVk
{ 7Nt6}${=z
sFileName = value; [e;c)XS[
} zM2_z
Q?]-/v
E8]kd
public int getNSplitter() k?;B1D8-n
{ j NkobJ1
return nSplitter; fKOC-%w
} :SvgXMY@
z6;6 o!ej
b,uudtlH
public void setNSplitter(int nCount) ![9umsx
{ #l#8-m8g)
nSplitter = nCount; K:(E"d;
} $bsD'Io
} F;sZc,Y,^
1j?+rs+o-
_|I`A6`=
/* jWqjGX`
**Utility.java \x;`8H
*/ = 4 wf
package NetFox; ?Es(pwJB
SZ(]su:
(]N- HN]v
public class Utility { qPF`=#
cogIkB&Ju
,u_ Z0S M
public Utility() 7B{LRm6;Vu
{ d=d*:<Zx
7oV$TAAf
P+bA>lJd
} !!?TkVyEyM
}WDzzjDR+
//线程睡眠 k{ ~0BK
public static void sleep(int nSecond) TP{2q51yM
{ B"?ivxM:U
try{ #.j}:
Thread.sleep(nSecond); T:I34E[
} 7m:ZG
catch(Exception e) (NC]S
{ E.eUd4XG
e.printStackTrace (); _9:r4|S
} 2mEvoWnJ
} dJ>~
cp$GP*{@
//日志 "Tz'j}< 9C
public static void log(String sMsg) Fj4>)!^kM
{ .bY R
System.err.println(sMsg); `IV7\}I|
} R9\ )a2
Yhte&,D"
n#^ii/H
public static void log(int sMsg) 0TWd.+
{ g5:?O,?
System.err.println(sMsg); 'S%H"W\
} {hFH6]TA
} $Da?)Hz'F
y#zO1Nig`
76cLf~|d~
/* 50""n7I<%
**TestMethod.java H)+QkQb}
*/ w)C5XX30;
package NetFox; S#:l17e3
N@0cn q:"
ny1;]_X_
public class TestMethod { +\]Gu(z<
)M><09
DS=$* Trk
public TestMethod() `vZX"+BAh
{ ///xx/weblogic60b2_win.exe Y'C1L4d
try{ =M=v; ,I-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EKus0"|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2Gh&h(
SiteFileFetch fileFetch = new SiteFileFetch(bean); $C{,`{=
fileFetch.start(); =;Dj[<mJ45
} ly:2XvV3~
catch(Exception e){e.printStackTrace ();} T~L&c
3$wK*xK
CEW1T_1U<\
} LXqPNVp#
EF6h>"']/
Cxeam"-HTt
public static void main(String[] args) ?4^ 0xGyE
{ V503
new TestMethod(); Y (pUd3y
} tI)|y?q
} _n1[(I
点击下载更多相关资料