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)); [+!&iN
} qB&Je$_uh
for(int i=0;i<nEndPos.length-1;i++) |.L_c"Bc
{ !Lw]aHb
nEndPos = nStartPos[i+1]; @PctBS<s
} d`~~Ww1
nEndPos[nEndPos.length-1] = nFileLength; Iga#,k+%
} nd7g8P9p
} M>}_2G]#F
PC|ul{[*}
D3%2O`9
//启动子线程 M|fV7g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1vtC4`
for(int i=0;i<nStartPos.length;i++) \O\q1 s~
{ n9n)eI)R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EdkIT|c{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }r!hm?e
nStartPos,nEndPos,i); Ps{vN ~}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ={+8jQqi1
fileSplitterFetch.start(); kX8NRPW
} F\|4zM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E+#<WK-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ivyaGAF}+o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T[#q0bv
nEndPos = " + nFileLength); R<(xWH
// fileSplitterFetch[nPos.length-1].start(); To5hVL<Ex"
HIx%c5^
;BYuNQr
//等待子线程结束 ]5Dh<QY&.
//int count = 0; qZ&~&f|>e
//是否结束while循环 aB?usVoS
boolean breakWhile = false; egURRC!
+jyGRSo
:7mHPe}(
while(!bStop) a^pbBDi W
{ .Y"F3 R
write_nPos(); 'W yWO^Bdk
Utility.sleep(500); N5h9){Mx
breakWhile = true; :O$bsw:3w<
H-U_
&i.sSqSI5
for(int i=0;i<nStartPos.length;i++) x!\q69ndv
{ nosD1sS.K8
if(!fileSplitterFetch.bDownOver) zsJermF,O
{ j49Uj}:j
breakWhile = false; M +r!63T
break; $Ery&rX.
} 7B (%2
} g\ vT7x
if(breakWhile) 9 fYNSr
break; l $"hhI8
lg~7[=%k#
=I)43ahd
//count++; 2wHbhW[
//if(count>4) +E_yEH7_)
// siteStop(); ne/JC(
} XW" 0:}`J
vIbM@Y4 '?
kuV7nsXiQ
System.err.println("文件下载结束！"); 2R.LLE
} oSC'b%
catch(Exception e){e.printStackTrace ();} Mjy:k|aY"
} OmO#} k<
I4{xQI
HOF$(86zqA
//获得文件长度 wz*iwd-
public long getFileSize() d6YXITL)\>
{ Qop,~yK
int nFileLength = -1; ,7]hjf_h
try{ qul#)HI
URL url = new URL(siteInfoBean.getSSiteURL()); "+- 'o+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <ak[`]
httpConnection.setRequestProperty("User-Agent","NetFox"); YAOfuas]j
L ,dh$F
Y(.e e%;,
int responseCode=httpConnection.getResponseCode(); :~vodh
if(responseCode>=400) Y \-W`
{ ehr-o7](
processErrorCode(responseCode); 6FA+qYSV
return -2; //-2 represent access is error 'Oue 1[
} zVq!M-e
?K>)bA&l'
30!DraW8
String sHeader; yx :^*/
-AdDPWn
}kqh[`:
for(int i=1;;i++) ,X4+i8Yc
{ W2 -%/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oS fr5 i
//Utility.log(in.readLine()); (Xh<F
sHeader=httpConnection.getHeaderFieldKey(i); gEd A hfx
if(sHeader!=null) $nO~A7
{ $3^M-w
if(sHeader.equals("Content-Length")) Q[biy{(b8
{ XB7Aa)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CUu Owx6%
break; &zdS9e-fF
} 1;ttwF>G7
} H5}61JC/z
else cag5w~Px
break; Zv;nY7B
} ]F4QZV( M
} /iU<\+ H
catch(IOException e){e.printStackTrace ();} .SD-6GVD
catch(Exception e){e.printStackTrace ();} z1mB Hz6
o5o myMN
Vp/XVyL}R
Utility.log(nFileLength); >Ku4Il+36
vB8$Qx\J
K81X32Lm'
return nFileLength; -V/y~/]J
} L|CdTRgRCB
<=M5)#
I%YwG3uR
//保存下载信息（文件指针位置） 1<r!9x9G
private void write_nPos() 5whW>T
{ |>;PV4])(
try{ 8z`ZHn3=
output = new DataOutputStream(new FileOutputStream(tmpFile)); ieZ$@3#&z
output.writeInt(nStartPos.length); 0=$/
for(int i=0;i<nStartPos.length;i++) ):$KM{X
{ .-Lrrk)R+
// output.writeLong(nPos); "ko*-FrQ
output.writeLong(fileSplitterFetch.nStartPos); \l GD8@,x
output.writeLong(fileSplitterFetch.nEndPos); zZCl]cql
} x%viCkq
output.close(); jY=y<R_oK
} m!FuC=e
catch(IOException e){e.printStackTrace ();} rN}pi@
catch(Exception e){e.printStackTrace ();} MQoA\
} /vSGmW-*
&-=~8
>(RkoExO/
//读取保存的下载信息（文件指针位置） ojM'8z0Hn
private void read_nPos() EO!,rB7I
{ W.j^L;
try{ }yT/UlU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cW%)C.M
int nCount = input.readInt(); 6Z_V,LD9L
nStartPos = new long[nCount]; L$PbC!1
nEndPos = new long[nCount]; PuNL%D
for(int i=0;i<nStartPos.length;i++) $s7U |F,I
{ syX?O'xJ
nStartPos = input.readLong(); v9f+ {Y%-
nEndPos = input.readLong(); s5*4<VxQN.
} )g@+ MR
input.close(); Ey=2zo^F
} y0xBNhev
catch(IOException e){e.printStackTrace ();} =Y2 Rht
catch(Exception e){e.printStackTrace ();} }097[-g7
} IWv(GQx
cEL:5*cAU}
$Tbsre\MJ
private void processErrorCode(int nErrorCode) ._rPM>B?
{ BE0l2[i?
System.err.println("Error Code : " + nErrorCode); yJ?=##
} h.Qk{v
w9|x{B
|+Wn5iT
//停止文件下载 Q:P)g#suc
public void siteStop() (_pw\zk>
{ c6:uM1V{
bStop = true; n-9xfn0U~#
for(int i=0;i<nStartPos.length;i++) r?DCR\Jq
fileSplitterFetch.splitterStop(); m"!SyN}&9?
O\<zQ2m
y.Z_\@
} Q/|.=:~FO
} @rGY9%E
//负责部分文件的抓取 i]MemM-
**FileSplitterFetch.java mu\1hKq;B
*/ daSe0:daJ
package NetFox; ,b5'<3\
\c\~k0u
&PJ;B)b
import java.io.*; KS*,'hvY
import java.net.*; W`x.qumN
GFFwk4n1
}ktIG|GC
public class FileSplitterFetch extends Thread { D9+qT<ojN
Hhtl~2t!0
y,:WLk~
String sURL; //File URL |Ahf 01
long nStartPos; //File Snippet Start Position 1{N+B#*<[X
long nEndPos; //File Snippet End Position v?."`,e
int nThreadID; //Thread's ID 0d+n[Go+S
boolean bDownOver = false; //Downing is over ChK-L6
boolean bStop = false; //Stop identical xN*k&!1&
FileAccessI fileAccessI = null; //File Access interface eWFkUjz
J$6WUz:?
Rrh6-]A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eKOEOm+
{ +c%jOl
this.sURL = sURL; nT?+^Ruc
this.nStartPos = nStart; @aQ:3/
this.nEndPos = nEnd; 9\EW~OgTu
nThreadID = id; vb^fx$V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iZG-ca
} !L.R"8!
|tAkv
kTH""h{
public void run() _&]7
{ n#6{K6}k~
while(nStartPos < nEndPos && !bStop) &pY'
{ t]SB.ja
^N^G?{EV/#
W(]A^C=/
try{ I/w;4!+)
URL url = new URL(sURL); {ENd]@N*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8=$XhC
httpConnection.setRequestProperty("User-Agent","NetFox"); +(=-95qZ
String sProperty = "bytes="+nStartPos+"-"; <( OHX3~
httpConnection.setRequestProperty("RANGE",sProperty); =6U5^+|d
Utility.log(sProperty); CzG[S\{+
^##j {h7
/Pextj<
InputStream input = httpConnection.getInputStream(); *sldv
//logResponseHead(httpConnection); $,K@xq5
oz=V|7,
ho$}#o
byte[] b = new byte[1024]; A5j?Yts
int nRead; EmaS/]X[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LilK6K
{ +ZbNSN=
nStartPos += fileAccessI.write(b,0,nRead); bVz<8b6h'-
//if(nThreadID == 1) JOG-i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2->Lz
} )Wle CS_
]A}ZaXd
D SX%SE)
Utility.log("Thread " + nThreadID + " is over!"); NxF:s,a6
bDownOver = true; lD0a<L3
//nPos = fileAccessI.write (b,0,nRead); x%s1)\^A
} 7>z {2D
catch(Exception e){e.printStackTrace ();} WyOav6/*K^
} OCu_v%G0
} ,Z @I"&H
rrz([2E2
Lxv;[2XsW)
//打印回应的头信息 C)c*s C5N
public void logResponseHead(HttpURLConnection con) oUn+tu:
{ a&0g0n6
for(int i=1;;i++) 8x-19#
{ 3Qd/X&P
String header=con.getHeaderFieldKey(i); qqo#H O
if(header!=null) p@O Ip
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QDW,e]A
Utility.log(header+" : "+con.getHeaderField(header)); }'tJc $!
else k9oi8G'g~
break; c*B< - l<5
} Y=|p}>.}
} V|@bITJ?7
*lA+-gkK*
DN)o|p
public void splitterStop() C-S>'\|8
{ |pS]zD
bStop = true; EpO2%|@
} m8PS84."]M
N$Ad9W?T
=PY{Elf
} UUDHknm"
.s>@@m-
1OExa<Zq
/* 5qH*"i+|s
**FileAccess.java Z[w}PN,xV
*//文件访问(定位，写) ?7V~>i8[
package NetFox; l!XCYg@67
import java.io.*; )EB+(c~E
)bih>>H
/0qbRk i
public class FileAccessI implements Serializable{ B<L7`xL
niCK(&z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +kd1q
RandomAccessFile oSavedFile; O'IU1sU
long nPos; ms5?^kS2O
[u!n=ev
zMA;1Na
public FileAccessI() throws IOException \~A qA!)6
{ n"RV!{&
this("",0); g(tVghHxt$
} 8Yk*$RR9
17?YN<
.Ja].hP
public FileAccessI(String sName,long nPos) throws IOException ^wWbW&<Tg
{ ;6``t+]q
oSavedFile = new RandomAccessFile(sName,"rw"); 1|4,jm$
this.nPos = nPos; 8cOft ;|qB
oSavedFile.seek(nPos); 'I/_vqp@
} DFWO5Y_
%gO/mj3*
2kDY+AN;
public synchronized int write(byte[] b,int nStart,int nLen) 04dz?`HuB
{ -O\i^?lD;
int n = -1; =3(Auchl$Y
try{ #at`7#K@
oSavedFile.write(b,nStart,nLen); tgG*k$8z
n = nLen; R`c[?U
} {rR(K"M
catch(IOException e) :Q"|%#P
{ Gqd|F>
e.printStackTrace (); V($V8P/
} "&k(lQ4
Dj96t5R
<$e|'}>A
return n; exhU!p8
} .+u b\
T#-;>@a}
h*l$!nEN
} SdYf^@%}F
` 'Qb?F6
[-$ Do
/* ?'P}ZC8P
**SiteInfoBean.java .c-a$39
*/ dW4jkjap
package NetFox; ;9k>;g3m
HCN/|z1Xq
T3P9
public class SiteInfoBean { #_35bg4h{
JnsJ]_<
RJ3oI+gI
private String sSiteURL; //Site's URL '3672wF/
private String sFilePath; //Saved File's Path 4`#Q
private String sFileName; //Saved File's Name 2g{tzR_j
private int nSplitter; //Count of Splited Downloading File x>[]Qk^?q
W\kli';jyC
^MvuFA,C
public SiteInfoBean() EpAgKzVpJ
{//nSplitter的缺省值为5 h) Wp
//default value of nSplitter is 5 ^-Od*DTL
this("","","",5); hU#e\L 7
} \A[l(aB
TsTc3
}'x;J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 06pvI}
{ O6;"cUv
sSiteURL= sURL; Tsg9,/vXM
sFilePath = sPath; (P)G|2=
sFileName = sName; q;'f3Y
this.nSplitter = nSpiltter; 5^Qa8yA>7
YqX$a~
nzflUR{`-
} O{LCHtN
'{d@Gc6.
92DM1~ *
public String getSSiteURL() dgw.OXa
{ R_PF*q2 '
return sSiteURL; 9wWBE<}>u
} ]1!" q40)]
q7X]kr*qx
aas.-NT
public void setSSiteURL(String value) y"JR kJ
{ Uq .6h
sSiteURL = value; [r/zBF-.
} WkTJ M
|H5.2P&9-5
Z4] n<~o
public String getSFilePath() 2zTi/&K&
{ @[n#-!i
return sFilePath; kTvM,<
} ,'X"(tpu@
XNJ4T]><
s\-,RQ1
public void setSFilePath(String value) jo`ZuN{
{ g":[rXvId
sFilePath = value; c$g@3gL
} tq3_az ~1
sl]<A[jR
Zl9@E;|=
public String getSFileName() WTvUz.Et
{ -R`{]7V
return sFileName; "D(Lp*3hj&
} {D+mr[ %
|mb2<!ag{
>@YefNX6
public void setSFileName(String value) A lU^,X
{ {7NGfzwp;6
sFileName = value; A6&*VD
} `AJ[g>py^|
<L&EH@T
:L[>!~YG_n
public int getNSplitter() #oUNF0L@6
{ ;P@]7vkff
return nSplitter; /).{h'^Hq\
} xnP!P2
J+6zV m
~3&{`9Y
public void setNSplitter(int nCount) rpR${%jc
{ z|l*5@p
nSplitter = nCount; P?54"$b
} '%NglC[J
} E[H
G=zWhqieh
u^80NR
/* FfoOJzf~o
**Utility.java ]\$/:f-2
*/ OmYVJt_
package NetFox; wKV4-uyr
"W|A^@r}
($[wCHU`!
public class Utility { HgI!q<)
4fEDg{T
g)D_!iz
public Utility() )9QtnM
{ UX 1 )((
c'2d+*[
1yy?1&88S
} kB\{1;
jc}G+|`
//线程睡眠 &d#R'Z
public static void sleep(int nSecond) VtreOJ+
{ A'WR!*Yt
try{ 7e/+C{3v
Thread.sleep(nSecond); sDY~jP[Oa
} G0cG%sIl
catch(Exception e) -N *L1Zj
{ cr7MvXF-
e.printStackTrace (); /7Q|D sa
} 5j%G7.S\
} |{jT+
!3ggQG!e
//日志 $o^Z$VmL
public static void log(String sMsg) k9|5TLXq?
{ /?\3%<vn
System.err.println(sMsg); P&-o>mM
} bS.w<V Ew
+n3I\7G>
p{FI_6db
public static void log(int sMsg) v9$!v^U"D
{ B@,9Cx564
System.err.println(sMsg); [,%=\%5
} S}m_XR]
} ?GhyVXS y.
FhE{khc#
G)3I+uxn
/* 'j1e(wq
**TestMethod.java >4 OXG7.&f
*/ O 4 !$
package NetFox; {K(mfTqm
a"8[,A3
9g92eKS
public class TestMethod { |(7}0]BP0
6CJMQi,kn
v gN!9
public TestMethod() %+7]/_JO&
{ ///xx/weblogic60b2_win.exe 0p.bmQSH
try{ _IH" SVub
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c:[k+_Zr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t [QD#;
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?KT{H(rU
fileFetch.start(); 3v* ~CQy9
} }d$-:l,w
catch(Exception e){e.printStackTrace ();} "S#FI
Vej$|nF
:<%bAn
} Iv`IJQH>
zF&VzNR2
*Cy54Z#
public static void main(String[] args) S0$^|/Sr
{ 6&3,fSP
new TestMethod(); HL)!p8UHJ
} jX53 owZ
} kmB!NxF>)F
点击下载更多相关资料