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)); 0?,EteR
} .M:,pw"S]
for(int i=0;i<nEndPos.length-1;i++) *o"F.H{#N
{ +< BAJWU
nEndPos = nStartPos[i+1]; m}Tu^dy
} 8Yq6I>@!
nEndPos[nEndPos.length-1] = nFileLength; 1ygu>sKS&A
} m U7Ad"
} "c\T
S2jo@bp!
NX)7g}S
//启动子线程 gWgK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qLYv=h$,
for(int i=0;i<nStartPos.length;i++) d2X#_(+d
{ V=(4 c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]g?G0m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _IpW&
nStartPos,nEndPos,i); HTx7._b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FLy|+4D_%4
fileSplitterFetch.start(); , PN?_N
} 103^\Av8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k )){1O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B u4N~0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *QLl jGe
nEndPos = " + nFileLength); 4\sS
// fileSplitterFetch[nPos.length-1].start(); d G:=tf&1R
>b*Pd *f
|Ca$>]?
//等待子线程结束 {8I93]
//int count = 0; Uk*s`Y
//是否结束while循环 ol`]6"Sc
boolean breakWhile = false; ^Gs!"Y
kf5921(P
PrN?;Z.
while(!bStop) yx/:<^"-$
{ NmtBn^t
write_nPos(); %8{' XJ!
Utility.sleep(500); yY_]YeeR
breakWhile = true; ]Dx?HBM"DC
kt;X|`V{5z
=}c~BHT
for(int i=0;i<nStartPos.length;i++) [BV{=;iD
{ n}MG
if(!fileSplitterFetch.bDownOver) VCc4nn#
{ dd4yS}yBlR
breakWhile = false; kP;Rts8JD
break; Vl9\&EL
} b$gDFNa
} )UJ]IB-Q|1
if(breakWhile) \-sDRW
break; EKoCm)}d
kc"U)>
)0d3sJ8
//count++; +Tu:zCv.
//if(count>4) Bq@G@Qi
// siteStop(); cIgFSwQ4
} ,:z@Ji
}l[t0C t
,[Ytl
System.err.println("文件下载结束！"); DTr0u}m
} Vx#xq#wK
catch(Exception e){e.printStackTrace ();} Tp0Tce/
} %|,j'V$
D@j `'&G
TkQ05'Qc
//获得文件长度 J\ 3~
public long getFileSize() 74Kl!A
{ MOOL=Um3
int nFileLength = -1; cxmr|-^
try{ @P@t/
URL url = new URL(siteInfoBean.getSSiteURL()); ^R2:Z&Iv%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ("9)=x*5
httpConnection.setRequestProperty("User-Agent","NetFox"); 7v\OS-
#D}NT*w/
]7br*t^zv
int responseCode=httpConnection.getResponseCode(); _|s{G
if(responseCode>=400) ^,`yt^^A
{ b8`O7@ar
processErrorCode(responseCode); *.~M#M 9c
return -2; //-2 represent access is error 5B@&]-'~
} m$$U%=r>@
NVOY,g=3X
-aec1+o
String sHeader; o!j? )0d
O"{NHNG\oT
7W 4[1
for(int i=1;;i++) Wk$%0xZ7
{ ~>qcV=F^d,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *d)B4qG
//Utility.log(in.readLine()); XLOk+Fn
sHeader=httpConnection.getHeaderFieldKey(i); $)PNf'5Zg
if(sHeader!=null) :MJTmpq,
{ rVZkG,Q
if(sHeader.equals("Content-Length")) 1 "4AS_Q
{ 9v/1>rziE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `XI1,&Wp7
break; `+i<:,z-gs
} $e0sa=/
} J/)Q{*`_
else sdrE4-zd
break; ZfIQ Fh>
} g9 g &]
} j1>1vD-`T
catch(IOException e){e.printStackTrace ();} T}U`?s`)
catch(Exception e){e.printStackTrace ();} zi<C5E`
XFH7jHnL+U
,Y}HP3
Utility.log(nFileLength); .,feRK>3
Vbz$dpT
*n}{)Ef
return nFileLength; >a]{q^0
} X$J
%m{h1UQQ+
WG1x:,-
//保存下载信息（文件指针位置） l? 7D0
private void write_nPos() d)9=hp;,V
{ o2&mhT
try{ ,@(lYeD"
output = new DataOutputStream(new FileOutputStream(tmpFile)); z!?xz
output.writeInt(nStartPos.length); $1/yc#w u
for(int i=0;i<nStartPos.length;i++) ql^n=+U
{ h\:"k_u#
// output.writeLong(nPos); 7!z0)Ai_>=
output.writeLong(fileSplitterFetch.nStartPos); !~PV\DQN
output.writeLong(fileSplitterFetch.nEndPos); vr2tMD
} W!htCwnkF
output.close(); .y|*
} A)'{G
catch(IOException e){e.printStackTrace ();} 9Yd<_B#
catch(Exception e){e.printStackTrace ();} Ptn0;GC
} /_>S0
$xNZ.|al
G4]T
//读取保存的下载信息（文件指针位置） Qp]V~s(
private void read_nPos() arRbq!mO
{ 51l:
try{ kwWDGA?zFB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S0du,A~
int nCount = input.readInt(); arET2(h
nStartPos = new long[nCount]; r ",..{
nEndPos = new long[nCount]; =`99ez+y
for(int i=0;i<nStartPos.length;i++) FL9Dz4
{ O_*%_S}F&
nStartPos = input.readLong(); 3Vs8"BFjz
nEndPos = input.readLong(); 0.=dOz r
} M;-PrJdyt
input.close(); 7S}NV7
} UM3}7|
catch(IOException e){e.printStackTrace ();} &r doMc;
catch(Exception e){e.printStackTrace ();} Qw}uB$S>
} u{o3
RG0kOw0
l|j
private void processErrorCode(int nErrorCode) fX2sjfk
{ F}wy7s2i
System.err.println("Error Code : " + nErrorCode); P XKEqcQR
} whxTCIV
+DU^"q=
<Z5-?wgf9
//停止文件下载 _Dr9 w&;<
public void siteStop() L7;8:^ v
{ ($'W(DH4
bStop = true; < KGq
for(int i=0;i<nStartPos.length;i++) _wH>h$E
fileSplitterFetch.splitterStop(); %<8`(Uu5
HCfme<'
;x%"o[[>
} EMQGP<[
} 4a}[&zm(5
//负责部分文件的抓取 0xVw{k}1U
**FileSplitterFetch.java V^Y'!w\LGI
*/ }C4wED.
package NetFox; GXC,p(vbE
_NefzZWUJ
ttOk6-
import java.io.*; ~=va<%{ U
import java.net.*; VWq]w5oQO
.DNPL5[v
v%:VV*MxF
public class FileSplitterFetch extends Thread { TZ&X0x8
CRBj>
vjjVZ
String sURL; //File URL J3`0i@
long nStartPos; //File Snippet Start Position IjGPiC
long nEndPos; //File Snippet End Position H-vHcqFx3
int nThreadID; //Thread's ID d~1uK-L]*
boolean bDownOver = false; //Downing is over rk6K0TQ8
boolean bStop = false; //Stop identical 27k(`{K
FileAccessI fileAccessI = null; //File Access interface _j+!Fd
a`L:E'|B9
m9vX8;.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eU\xOTl~<{
{ _f'v>"K
this.sURL = sURL; 85YUqVi9
this.nStartPos = nStart; 84vd~Cf9
this.nEndPos = nEnd; aaP_^m O
nThreadID = id; NV7k@7_{B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !_vxbfZO
} SE'!j]6jI
+D@5zq:5
\?pyax8
public void run() tI1OmhNN
{ LH)XD[
while(nStartPos < nEndPos && !bStop) I)tiXcJw
{ ]?pQu'-(
(`S^6-^
M@#T`aS
try{ 9.8%Iw
URL url = new URL(sURL); vfc:ok1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s3HVX'
httpConnection.setRequestProperty("User-Agent","NetFox"); -8xf}v~u
String sProperty = "bytes="+nStartPos+"-"; Wl |5EY
httpConnection.setRequestProperty("RANGE",sProperty); As<B8e]
Utility.log(sProperty); +x(#e'6p
R*:>h8
[% C,&h5
InputStream input = httpConnection.getInputStream(); s bj/d~$N
//logResponseHead(httpConnection); Keozn*fzI
kk%32(By
CJ* D
byte[] b = new byte[1024]; _Z23lF9
int nRead; 8LbwEKl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )\|+G5#`
{ ]QhTxrF"
nStartPos += fileAccessI.write(b,0,nRead); W7^[W.
//if(nThreadID == 1) 5BJE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -~mgct5
} $#q`Y+;L2
#L~i|(=U5
&)Xc'RQ.C
Utility.log("Thread " + nThreadID + " is over!"); Lm TFvZ
bDownOver = true; &^r>Q`u
//nPos = fileAccessI.write (b,0,nRead); OvtE)ul@
} DMM<,1
catch(Exception e){e.printStackTrace ();} 51SmoFbMz
} X*QS/\
} P(hGkY=(
X_]rtG
BH">#&j[
//打印回应的头信息 maXg(Lu
public void logResponseHead(HttpURLConnection con) 5J10S
{ $@>0;i::
for(int i=1;;i++) Ix5&B6L8
{ _!nsEG VV
String header=con.getHeaderFieldKey(i); b6bs .
if(header!=null) ;f[lq^eV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l4>^79**
Utility.log(header+" : "+con.getHeaderField(header)); U[@y8yN6M
else m^k0j/
break; zaqX};b
} |_V(^b}
} y0%1YY
U ? +_\
4J2^zx,H
public void splitterStop() }yz>(Pq
{ "8xAe0-4
bStop = true; ]:P7}Kpb
} (N7uaZ?Z
S6TNu+2w4
bGPE0}b
} ~HZdIPcC
e$# *t
CKYg!\g(:
/* =p+y$
**FileAccess.java E TT46%Y
*//文件访问(定位，写) S<tw5!tJ
package NetFox; Lo%n{*if
import java.io.*; Gv:~P_vBH[
#BC"bY
b 7UJ
public class FileAccessI implements Serializable{ >STtX6h
]A*}Dem*5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rE3dHJN;
RandomAccessFile oSavedFile; UUah5$Iy
long nPos; ;cor\R
;]{ee?Q^ld
B,%Vy!o
public FileAccessI() throws IOException wA) Hot
{ Lc3&\q e
this("",0); 8-q^.<9
} ]Bhy=1
oBzl=N3<
{/'T:n#
public FileAccessI(String sName,long nPos) throws IOException y0zMK4b
{ +P/kfY"
oSavedFile = new RandomAccessFile(sName,"rw"); W(,j2pU
this.nPos = nPos; 3/G^V'Yu
oSavedFile.seek(nPos); 34@[ZKJ5
} 8v4}h9*F"7
Sc)^k
_?{7%(C
public synchronized int write(byte[] b,int nStart,int nLen) JJ?{V:
{ Ei;tfB
int n = -1; C|'DKT4M&
try{ ([>ecS@eO
oSavedFile.write(b,nStart,nLen); K7 e~%mY
n = nLen; [a=exK
} iI3:<j l
catch(IOException e) J2UQq7-y
{ q7R]!zk
e.printStackTrace (); gFDnt
} ]%Q!%uTh
k6G _c;V
I \:WD"
return n; &V"oJ}M/a
} !X>u.}?g
e+ xQ\LH
Sj9fq*
} jr6_|(0 i6
)vp0X\3q`
v+c>iI
/* d2k-MZuT6
**SiteInfoBean.java K/Q"Z*
*/ t@q'm.:uw<
package NetFox; +H)'(<
Q8p6n
.Y)[c.,j
public class SiteInfoBean { !Ok(mgV$/
-YRIe<}E -
F:{*4b
private String sSiteURL; //Site's URL HU3:6R&
private String sFilePath; //Saved File's Path m'4f'tbN
private String sFileName; //Saved File's Name ?J}Q&p.
private int nSplitter; //Count of Splited Downloading File $( hT{C,K
$] 6u#5
@MW@mP)#
public SiteInfoBean() +-9vrEB
{//nSplitter的缺省值为5 @6u/)>rI
//default value of nSplitter is 5 7|rH9Bc{U
this("","","",5); tne_]+
} sZ;|NAx)
D6 B-#u!M
@^{Hq6_`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kxe\H'rR
{ ]9@:7d6
sSiteURL= sURL; C2 N+X(
sFilePath = sPath; a#oROb-*~
sFileName = sName; 7Ai?}%b-
this.nSplitter = nSpiltter; sNf& "C!;
tUn>=>cWP
"wUIsuG/p
} m|*B0GW
!avol/*
bO~y=Pa\
public String getSSiteURL() eP{srP3 9
{ QX,$JM3
return sSiteURL; @gUp9ZwtH
} k.J%rRneN
`e[S Zj\
i'tMpS3
public void setSSiteURL(String value) Hv,|XE@Y
{ ^r}c&@
sSiteURL = value; ggso9ZlLu+
} FO{=^I5YA
*$p*'vR
2"/MM2s
public String getSFilePath() dFg>uo
{ JK,MK|
return sFilePath; V&Y`?Edc
} *k?:k78L
rPxRGoR
,H7X_KbFD4
public void setSFilePath(String value) "N4^ ^~s
{ )f8>kz(
sFilePath = value; {v={q1
} kHM Jh~
`sjY#Ua<
e=amh
public String getSFileName() 5eAZfe%H
{ 4&)sROjV=
return sFileName; %h.zkocM
} Bk8}K=%w
<JPN< Kv
cXweg;
public void setSFileName(String value) ,05PYBc3
{ y<`5
sFileName = value; d3%qYL_+a
} 7UTfafOGX
`IHP_IfR
)W\)37=.
public int getNSplitter() p.8bX
{ 79DNNj~
return nSplitter; ixTjXl2g
} jCd]ENl+_
]3r}>/2(
Upz)iOqLi
public void setNSplitter(int nCount) F`=p/IAJK
{ 0d2P
nSplitter = nCount; (3e.q'
} 4:MvC^X~z
} Jb,54uN
.G/Rh92
vG|!d+
/* z']6C9m}
**Utility.java xj5TnE9^
*/ KGt:
package NetFox; KpN]9d
XG#?fr}L
&YFe"C
public class Utility { >N&{DJmD
^} {r@F
*F$@!ByV
public Utility() TE`5i~R*
{ Va!G4_OT
^[hAj>7_8$
=OufafZb
} 7cc^n\c?Y
-jQ*r$iRE
//线程睡眠 hqRC:p#9
public static void sleep(int nSecond) 0kJ8H!~u
{ Y e0,0Fpw
try{ lHiWzt u
Thread.sleep(nSecond); ~[H8R|j "
} h!tpi`8\z
catch(Exception e) 2EgvS!"
{ @@R Mm$
e.printStackTrace (); }L0 [Jo:
} (bm^R-SbB
} fY]"_P
|v+z*}fKw
//日志 wv~:^v'
public static void log(String sMsg) @Y0ZW't
{ xMbgBx4+
System.err.println(sMsg); .!1[I{KU
} 3f=ZNJ>
sY<UJlDKT
r8"2C#
public static void log(int sMsg) =gF035
{ 6R :hsC$
System.err.println(sMsg); w!lk&7Q7Z
} zJXK:/
} Dgz,Uad8f
'Agw~ &$
+~n:*\
/* #7;?Ls
**TestMethod.java 2: QT`e&
*/ 628iN%[-
package NetFox; 5V 2ZAYV
-!!]1\S*Y
y)zZ:lyIq
public class TestMethod { ^cZ< .d2
GVhqNy
cs6oD!h
public TestMethod() <M9NyD`
{ ///xx/weblogic60b2_win.exe 'p5M|h\:T
try{ ILr=<j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +cfcr*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y. J!]|
SiteFileFetch fileFetch = new SiteFileFetch(bean); "U^m~N9k{
fileFetch.start(); `h'+4
} lEl.'X$
catch(Exception e){e.printStackTrace ();} A~xw:[zy$a
'goKYl#1Q
+yI$4MY
} \me5"ZU
XQ~Xls%]
_-BP?'lN
public static void main(String[] args) D\M"bf>q1
{ 3IRur,|'
new TestMethod(); .xqi7vVHZ
} PVg<Ovi^d
} pO *[~yq5
点击下载更多相关资料