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)); [=E
} &R[ Mc-2
for(int i=0;i<nEndPos.length-1;i++) -d~4A
{ FK:;e lZ
nEndPos = nStartPos[i+1]; _g+JA3sIJ
} Vu)4dD!
nEndPos[nEndPos.length-1] = nFileLength; |*oZ_gI
} ))R5(R
} q+Lr"&'Q
)T/0S$@
DNOueU
//启动子线程 f1`gdQ)H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !Z`j2 e}
for(int i=0;i<nStartPos.length;i++) aUzBV\Yd}
{ :V1W/c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MC?,UDNd%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gcE|#1>
nStartPos,nEndPos,i); J,V9k[88
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )2pbpbWX>
fileSplitterFetch.start(); {J{+FFsr(
} V[{6e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CpA|4'#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qS403+Su1=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dq7x3v^"ZG
nEndPos = " + nFileLength); yL%K4$z
// fileSplitterFetch[nPos.length-1].start(); y-T| #
^M3~^lV
)`SES."
//等待子线程结束 !Nu<xq@!
//int count = 0; ?p9VO.^5
//是否结束while循环 fdxLAC
boolean breakWhile = false; VO,!x~S!
RS"H8P4W
e>7]w,*|
while(!bStop) u}>#Eb
{ &+a9+y
write_nPos(); /mXBvY
Utility.sleep(500); B\<Q ;RI2;
breakWhile = true; *-+&[P]m
3;)>Fs;
1q~+E\x
for(int i=0;i<nStartPos.length;i++) 6BY-^"W5`
{ O?NeSx1
if(!fileSplitterFetch.bDownOver) 3Vsc 9B"w
{ *YW/_
breakWhile = false; AK&S5F>D+B
break; @En^wN
} sJ#4(r`
} /d0K7F
if(breakWhile) j;%-fvd;
break; oE<`VY|
Wc,_RN-
*7*lE"$p
//count++; y#>,+a#5
//if(count>4) nnCGg+l
// siteStop(); ~1cnE:x;V
} ie;]/va
R#xCkl-
UQ8M~x5$3%
System.err.println("文件下载结束！"); `kOD[*
} y]2qd35u_A
catch(Exception e){e.printStackTrace ();} &yGaCq;0
} UUSq$~Ct
u*e.yN
bnm P{Ps
//获得文件长度 D Gr> 2
public long getFileSize() BsBK@+ZyI
{ {xwm^p(f
int nFileLength = -1; 2uG0/7
try{ s<*XNNE7
URL url = new URL(siteInfoBean.getSSiteURL()); 0F@"b{&0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EM]s/LD@%
httpConnection.setRequestProperty("User-Agent","NetFox"); MJ7Y#<u
+IrLDsd
aF)1Nm[
int responseCode=httpConnection.getResponseCode(); GRGzP&}@
if(responseCode>=400) ^sa#8^,K
{ jL(qf~c_
processErrorCode(responseCode); =3|O%\
return -2; //-2 represent access is error c05TsMF&O
} -%2[2p
;ToKJ6hN|*
HuB<k3#sPy
String sHeader; S7=Bd[4
pV.Av
Nqw&< x+
for(int i=1;;i++) >fe-d#!{
{ umD!2 w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); AP[|Ta
//Utility.log(in.readLine()); %R@X>2l/_
sHeader=httpConnection.getHeaderFieldKey(i); 7+]=-
if(sHeader!=null) &f!z1d-qg?
{ bx<RV7>0
if(sHeader.equals("Content-Length")) 6WV\}d:
{ GMMp|WV|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +hn+K1
break; }~#pEX~j*
} xB_!>SqF1U
} }MRd@ 0-?!
else MHSs!^/g5
break; 8dV=[+
} /<E5"Mm%
} Ge,;8N88
catch(IOException e){e.printStackTrace ();} Xua+cVc\y
catch(Exception e){e.printStackTrace ();} !vX D
yMyE s8
7G.#O}).b
Utility.log(nFileLength); *&?c(JU;<
HU%o6cw
K/A*<<r ~
return nFileLength; 8d?g]DEN)6
} "5;;)\o~
?z}=B
hZh9uI7.
//保存下载信息（文件指针位置） ^[]}R:
private void write_nPos() #Xhdn\7
{ P/xKnm~
try{ -`<kCW"
output = new DataOutputStream(new FileOutputStream(tmpFile)); XpmS{nb
output.writeInt(nStartPos.length); bA= |_Wt
for(int i=0;i<nStartPos.length;i++) >wb'QzF:
{ SGh1 DB
// output.writeLong(nPos); n3}!p'-CC
output.writeLong(fileSplitterFetch.nStartPos); Of{/t1o?
output.writeLong(fileSplitterFetch.nEndPos); KC(xb5x Y
} NLS%Sq
output.close(); /3eKN
} /GIxR6i
catch(IOException e){e.printStackTrace ();} ^\\Tx*#i
catch(Exception e){e.printStackTrace ();} GKvN* SU=
} t=_J9|
]04e1F1J
dYSr4pb
//读取保存的下载信息（文件指针位置） \cC%!4
private void read_nPos() I?"q/Ub~h
{ Vl%^H[]
try{ ._8KsuJG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); la( <8
int nCount = input.readInt(); T32+3wb"I
nStartPos = new long[nCount]; gN24M3{C
nEndPos = new long[nCount]; '3TW [!m
for(int i=0;i<nStartPos.length;i++) `9)t[7
{ Z-E`>
nStartPos = input.readLong(); *GxTX3i}vc
nEndPos = input.readLong(); jov:]Bic
} hGd<<\
input.close(); {Z3dF)>
} |~'IM3Jw(Y
catch(IOException e){e.printStackTrace ();} "`M?R;DH
catch(Exception e){e.printStackTrace ();} >tO`r.5u9
} RY c!~Wh~Y
t]$P1*I
Eq$&qV-?(
private void processErrorCode(int nErrorCode) w4W_iaU
{ +<xQM h8
System.err.println("Error Code : " + nErrorCode); }Z{=|rVE
} Ggl~nxz
,Y|^^?'j Q
bx]N>k J
//停止文件下载 .q[SI$qO/
public void siteStop() \2ZPj)&-E
{ %CS@g.H=_
bStop = true; f 1w~!O9
for(int i=0;i<nStartPos.length;i++) 8>X d2X
fileSplitterFetch.splitterStop(); dDm):Z*`b
)\6&12rj
X5X?&* %{
} 0j30LXI_
} T/^Hz4uA7
//负责部分文件的抓取 Jrg2/ee,*
**FileSplitterFetch.java U+)xu>I
*/ 3dht!7/
package NetFox; _<a7CCg
9uRFnzJVx
M9y<t'
import java.io.*; TUHi5K
import java.net.*; wD68tG$
\[gReaI
slg ]#Dy
public class FileSplitterFetch extends Thread { HPb]Zj
,$'])A?$
Ps%qfL\
String sURL; //File URL AtF3%Zv2
long nStartPos; //File Snippet Start Position Gm9hYhC8
long nEndPos; //File Snippet End Position N@Y ljz|
int nThreadID; //Thread's ID )RO<o O
boolean bDownOver = false; //Downing is over ~4s'0 w^
boolean bStop = false; //Stop identical KN tt
FileAccessI fileAccessI = null; //File Access interface cx}Q2S
$/=nU*pd
4m*M,#mV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GN!qyT
{ F)+{AQL
this.sURL = sURL; d}JP!xf%
this.nStartPos = nStart; 6KVnnK
this.nEndPos = nEnd; &^}6 9
nThreadID = id; |1ST=O7.LH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +)j1.X
} h$.:Uj8/
9lGOWRxR)
N\HQN0d9
public void run() tID%}Zv
{ &}?$i7x5
while(nStartPos < nEndPos && !bStop) ;5tazBy&:C
{ zo[[>MA
~mO62(8m
ep=qf/vd<
try{ ~=KJzOS,S
URL url = new URL(sURL); 0pJ ":Q/2)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZTU&,1Y;
httpConnection.setRequestProperty("User-Agent","NetFox"); n>A98NQ
String sProperty = "bytes="+nStartPos+"-"; 2Fz|fW_
httpConnection.setRequestProperty("RANGE",sProperty); VxY+h`4#
Utility.log(sProperty); (y?ITz9
=QK$0r]c'k
wMdal:n^
InputStream input = httpConnection.getInputStream(); GrTulN?
//logResponseHead(httpConnection); `)T~psT
:=8t"rO=W
em\ 9'L^
byte[] b = new byte[1024]; ,RgB$TcE
int nRead; /F4pb]U!*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C_4)=#@GU
{ y_HN6
nStartPos += fileAccessI.write(b,0,nRead); 2*N_5&9mE
//if(nThreadID == 1) ^Ve<>b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K"b`#xN(t
} b8%C*r7
K =wBpLB
qwK2WE%T
Utility.log("Thread " + nThreadID + " is over!"); F:D orE
bDownOver = true; c-g)eV|)S
//nPos = fileAccessI.write (b,0,nRead); $&"V^@
} ,SQZD,3v4
catch(Exception e){e.printStackTrace ();} *J+_|_0nlW
} Vpr/
} ~}!3G
A8q;q2
F[4;Xq
//打印回应的头信息 MB%Q WU
public void logResponseHead(HttpURLConnection con) \~BDm
{ 6m VuyI
for(int i=1;;i++) t^[8RhD
{ v3GwD00
String header=con.getHeaderFieldKey(i); M@3"<[g
if(header!=null) @JvPx0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @h*fFiY&{
Utility.log(header+" : "+con.getHeaderField(header)); eL4NB$Fb
else "wlt> SU
break; f>s?4
} r}0\}~'?c
} $t5V=}m>
P i Fm|
Fbu5PWhlc
public void splitterStop() RN)dS>$
{ 3SSm5{197
bStop = true; .e'eE
} 6Z`R#d #I
Cn>ADWpT&
k^ YO%_
} K9vIm4::d$
*]h`KxuO
}hYZ" A~
/* $''9K
**FileAccess.java +rIL|c}J
*//文件访问(定位，写) })w*m
package NetFox; 7HVZZ!>~
import java.io.*; kGL1!=>
l^d[EL+
RZe'Kw -
public class FileAccessI implements Serializable{ pGSai&
gPu2G/Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sHcTd>xS
RandomAccessFile oSavedFile; ]`bQW?
long nPos; MWNPPYww
11|Rdd+}
h(qQsxIOhS
public FileAccessI() throws IOException pDQ}*
{ lc_E!"1
this("",0); &QG6!`fK}3
} VdP`a(Yd;
i/b'4o=8
XX1Il;1G#
public FileAccessI(String sName,long nPos) throws IOException Iyd?|f"
{ T~fmk f$
oSavedFile = new RandomAccessFile(sName,"rw"); %+ FG,d
this.nPos = nPos; [>^PRs
oSavedFile.seek(nPos); =?h~.lo
} 7 Sa1;%R
}|B=h
2"fO6!hh
public synchronized int write(byte[] b,int nStart,int nLen) ^'p|!`:
{ A~Xq,BxCV
int n = -1; zZiJ 9 e
try{ }n7th
oSavedFile.write(b,nStart,nLen); bu&t'?zx!
n = nLen; aF|d^
} `z0{S!
catch(IOException e) -dv%H{
{ *WE1;msr
e.printStackTrace (); eUl/o1~mXa
} l{VSb92f
'xv8Gwf"
=&!HwOnp
return n; tA$)cg+.
} M0|'f'
hUz[uyt
N$TL;T>
} ;pD)m/$h`
q!f1~aG
s4%(>Q
/* rdnRBFt
**SiteInfoBean.java CSV;+,Vv
*/ PY3ps2^K.
package NetFox; >/<:Q &
v(leide
6DL[aD
public class SiteInfoBean { "4H8A=
fWF|,A>>b
^). )
private String sSiteURL; //Site's URL D;Gq)]O
private String sFilePath; //Saved File's Path OzT#1T1'c
private String sFileName; //Saved File's Name Dml*T(WM>
private int nSplitter; //Count of Splited Downloading File XJ!(F#zc
o{*ay$vA]
T\VNqs@
public SiteInfoBean() x90jw$\%7
{//nSplitter的缺省值为5 *?yJkJ"
//default value of nSplitter is 5 1!p/6
this("","","",5); yMLOUUWa8x
} >QHo@Zqj(
Gg\G'QU
XT,#g-oi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7ou46v|m5
{ VGw(6`|!
sSiteURL= sURL; :)jJge&^p
sFilePath = sPath; ;Qi }{;+
sFileName = sName; ~#}Dx :HH
this.nSplitter = nSpiltter; <DH*~tLp2
m}$+Hdk+7
BpO9As 1um
} ZyR_6n>L$
z"DkFvA
A>NsKWf{
public String getSSiteURL() XE}H3/2
{ %o?IsIys
return sSiteURL; Pw@olG'Ah
} 5&CDHc7Oj
rZ_>`}O2
VohhQ
public void setSSiteURL(String value) ]%RNA:(F'
{ P&*sB%B
sSiteURL = value; +VEU:1Gt
} )[&_scSa
@\(vX]
?IX!+>.H
public String getSFilePath() OlxX.wP
{ Q\{x)|{$
return sFilePath; &"uV~AM
} SW(q$i
DhI>p0* T
*.f2VQ~H
public void setSFilePath(String value) >+cVs:
{ <Wl(9$
sFilePath = value; ,/&Zw01dGN
} }tST)=M`
^T4Ay=~{
2 Tvvq(?T
public String getSFileName() h5|.Et
{ 2aNT#J"_
return sFileName; F5gObIJtuY
} Jx-wO/
>s*DrfX6
< /p8r
public void setSFileName(String value) Mo|wME#M
{ v4*rPGv
sFileName = value; % U`xu.
} ~3WL)%
Q |i9aE
`GQ{*_-
public int getNSplitter() RE46k`44
{ 6R}j-1 <n
return nSplitter; a0Oe:]mo\
} NB8&
1M%S gV-#
}4%/pOi:f
public void setNSplitter(int nCount) ]Ql 0v"` F
{ Az*KsY{/r
nSplitter = nCount; d<o.o?Vc
} US?Rr
} ~el-*=<m
_JGs}aQ
j kn^Z":
/* I#A2)V0P)
**Utility.java (!K+P[g
*/ NVIWWX9?
package NetFox; c^I0y!
#]KgUc5B
8IY19>4'5J
public class Utility { yOHXY&
0=U70nKr
S0@T0y#
public Utility() LZ~`29qw(
{ ~o15#Pfn/
T|'&K:[TJ
l\q} |o
} )ctr"&-
>w'$1tc?+F
//线程睡眠 %l9$a`&
public static void sleep(int nSecond) 7 Yv!N
{ mv Ov<x;l
try{ sy<iKCM\
Thread.sleep(nSecond); ahIE;Y\j'
} mVH,HqsXa
catch(Exception e) H:oQ
{ SX+RBVZU
e.printStackTrace (); #n})X,ip2
} 66ohmP@04Z
} ^7XAw: ?
}Zl"9A#K
//日志 ;[5r7 jHU
public static void log(String sMsg) k 'zat3#f
{ ,-#GX{!
System.err.println(sMsg); `<vxG4=62\
} ZCiY,;c
tEhr
x*8O*!ZZ
public static void log(int sMsg) h W.2p+
{ C|e+0aW
System.err.println(sMsg); -}<g-*m"q
} snMQ"ju
} +l\<?
T1~)^qQ
eK_*q-
/* ;) pl{_
**TestMethod.java ~$aTM_4
*/ 3IyZunFT
package NetFox; Pz~q%J
H7e /
?JqjYI{$
public class TestMethod { E$S`6+x`:a
|`]oc,1h@
O~'FR[J
public TestMethod() #8?^C]*{0
{ ///xx/weblogic60b2_win.exe };SV!'9s?~
try{ YOw?'+8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :EB,{|m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mTjm92
SiteFileFetch fileFetch = new SiteFileFetch(bean); b(T@~P/
fileFetch.start(); X4I]9t\
} xXOw:A'
catch(Exception e){e.printStackTrace ();} s-6:N9-
jH0Bo;
1xC`ZhjcD
} J:};n@<
~%P3Pp
e[4V%h
public static void main(String[] args) Yo'K pdn
{ (T;9us0
new TestMethod(); 1ih*gJPpj
} R+Lk~X^*l'
} >l2w::l%
点击下载更多相关资料