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)); Gj /3kS~@
} jUqy8q&
for(int i=0;i<nEndPos.length-1;i++) ?QDWuPhN
{ PZD>U)M
nEndPos = nStartPos[i+1]; rB%$;<`/
} =N|kn<h4
nEndPos[nEndPos.length-1] = nFileLength; 8%~t
} VIR.yh
} 5ZAb]F90
Q^Bt1C
D["MUB4l
//启动子线程 jRpdft
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2~;&g?T6
for(int i=0;i<nStartPos.length;i++) 0%;146.p
{ ^aRgMuU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~ekh1^evu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vY*\R0/a
nStartPos,nEndPos,i); Yp4c'Zk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *V;3~x!
fileSplitterFetch.start(); gK3Mms]}m
} - n6jG}01b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RX2{g^V7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pD@zmCU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i$-#dc2qY
nEndPos = " + nFileLength); sst,dA V$
// fileSplitterFetch[nPos.length-1].start(); HpexH{.u)
Ok%}|/P4
'?GQ~Bf<>
//等待子线程结束 ELh3^
//int count = 0; kYxS~Kd<
//是否结束while循环 ER{3,0U
boolean breakWhile = false; $'[q4wo<
\`xkp[C
*,\` o~
while(!bStop) P l{QOR
{ 9''p[V.3
write_nPos(); 1:= `Y@.S
Utility.sleep(500); w9#R'
breakWhile = true; xnq><4
qA/bg
^i:\@VA:
for(int i=0;i<nStartPos.length;i++) ]R_G{%
{ ev>oC~>s
if(!fileSplitterFetch.bDownOver) {sC=J hs-
{ fV ZW[9[
breakWhile = false; |Zq\GA
break; rvwy~hO"
} M>_= "atI
} I/UQ'xx
if(breakWhile) 77:'I
break; 8kW/DcLE
%TK&)Q% h5
O=jN&<rb
//count++; DPJh5d
//if(count>4) 5su.+4z\
// siteStop(); f(u&XuZ
} ]RFdLV?
g<[rH%\6fg
dA#{Cn;
System.err.println("文件下载结束！"); Y~"9L|`f/
} Ud3""C5B
catch(Exception e){e.printStackTrace ();} N5q725zJ
} ZcZ;$*
j.QHkI1.
z*.v_Mx
//获得文件长度 "jZm0U$,*
public long getFileSize() Qm);6X
{ cj(X2L
int nFileLength = -1; YlUpASW
try{ <FmBa4ONU
URL url = new URL(siteInfoBean.getSSiteURL()); XS0V:<+,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^&:'NR
httpConnection.setRequestProperty("User-Agent","NetFox"); O2H/rFx4
FWTx&Ip
MtG_9-
int responseCode=httpConnection.getResponseCode(); jpO38H0)
if(responseCode>=400) r69WD .
{ cTj~lO6
processErrorCode(responseCode); V<$*Y>;
return -2; //-2 represent access is error [$2qna2VP
} t&"5dM\
2xmT#m
<PD|_nZT
String sHeader; HtzMDGV<
qWB%),`j>
q 22/_nSC
for(int i=1;;i++) %}F"*.
{ zPQ$\$7xB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); om7`w ]
//Utility.log(in.readLine()); D9ywg/Q91
sHeader=httpConnection.getHeaderFieldKey(i); bhKV +oN
if(sHeader!=null) slSR=XOG
{ zH+<bEo=1=
if(sHeader.equals("Content-Length")) P|N?OocE
{ tQ0=p| T]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]hUKuef
break; ?-{IsF^
} )[DpK=[N^p
} ;xW{Ehq-h
else eG^z*`**
break; /'Bdq?!B&
} /\~W$.c
} M,L@k
catch(IOException e){e.printStackTrace ();} +UaO<L
catch(Exception e){e.printStackTrace ();} dP3VJ3+ %
t~~r-V":
kGj]i@(PA4
Utility.log(nFileLength); o*)@oU
drX4$Kdf]
&z0iLa4q)
return nFileLength; r!M#7FDs(
} vz,LF=s2
P6E1^$e
ok=40B99T
//保存下载信息（文件指针位置） ={xqNRVd
private void write_nPos() '5cZzC 2
{ feg`(R2
try{ dp< auA
output = new DataOutputStream(new FileOutputStream(tmpFile)); | /#'S&!U
output.writeInt(nStartPos.length); ;q&Z9lm
for(int i=0;i<nStartPos.length;i++) [EOMCH2Ki
{ w}b<D#0XC
// output.writeLong(nPos); GFY-IC+fc
output.writeLong(fileSplitterFetch.nStartPos); 'Ix5,^M}B
output.writeLong(fileSplitterFetch.nEndPos); g$gVm:=
} V*kznm
output.close(); d'q;+jnP
} R]VTV7D
catch(IOException e){e.printStackTrace ();} |3|wdzV
catch(Exception e){e.printStackTrace ();} o5V`'[c
} iGyVG41U
4Q/r[x/&C
A<;0L . J
//读取保存的下载信息（文件指针位置） I &cX8Tw
private void read_nPos() e Ri!\Fx
{ _jk|}IB;X
try{ ]t7ClT)n!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w=gQ3j#s
int nCount = input.readInt(); PgqECd)f
nStartPos = new long[nCount]; |/2LWc?
nEndPos = new long[nCount]; {!g?d<*
for(int i=0;i<nStartPos.length;i++) Xv]*;Bq:SK
{ hX %s]"
nStartPos = input.readLong(); +%x^RV}
nEndPos = input.readLong(); 4KZSL:A
} >5df@_'
input.close(); w4`!Te
} `GP3D~
catch(IOException e){e.printStackTrace ();} Ckw83X
catch(Exception e){e.printStackTrace ();} S{Rh'x\B
} frk7^5
8QPT\~
U=M#41J
private void processErrorCode(int nErrorCode) )ZviS.
{ UVnrDhd!0
System.err.println("Error Code : " + nErrorCode); Za34/ro/T
} -wBnwn-
0\QYf0o
|@OJ~5H/{
//停止文件下载 JPHUmv6
public void siteStop() a{5H33JA
{ .!!79 6hS
bStop = true; q^u6f?B
for(int i=0;i<nStartPos.length;i++) z{@=_5;
fileSplitterFetch.splitterStop(); A"`L~|&
%~ ;nlDw
kA1f[AL
} ,7QBJ_-;QJ
} Xk 5oybDI
//负责部分文件的抓取 @_G` Ok4
**FileSplitterFetch.java B<rPvM7a
*/ rrW! X q
package NetFox; !Jh*a *I}
BllDWKb
q`h7H][(A
import java.io.*; ryz/rf
import java.net.*; x0y%\
cvn-*Sj
(}VuiNY<3
public class FileSplitterFetch extends Thread { U[blq M
@F>[DW]O
`>dIF.
String sURL; //File URL qT 5WaO)
long nStartPos; //File Snippet Start Position YL;SxLY
long nEndPos; //File Snippet End Position ,ZLG7e
int nThreadID; //Thread's ID }3bQ>whF
boolean bDownOver = false; //Downing is over K lPm=
boolean bStop = false; //Stop identical U$MWsDn
FileAccessI fileAccessI = null; //File Access interface [B.W1 GL!
pq%t@j(X
wEZqkV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p!. /
{ F%w\D9+P
this.sURL = sURL; ftDVxKDE?S
this.nStartPos = nStart; e-&L\M
this.nEndPos = nEnd; GZ;Z
nThreadID = id; <m-Ni
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hB?U5J
} k?!TjBKm
kO /~i
/W7&U =d9
public void run() aY3pvOV
{ s{b0#[
while(nStartPos < nEndPos && !bStop) `[w}hFl~q
{ 2l]C55p)s
:-W$PIBe
JDIz28Ww
try{ VGq{y{(
URL url = new URL(sURL); pT|./ Fe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H&"_}
httpConnection.setRequestProperty("User-Agent","NetFox"); s0x@ u
String sProperty = "bytes="+nStartPos+"-"; kfH9Y%bOy
httpConnection.setRequestProperty("RANGE",sProperty); !NlB%cF
Utility.log(sProperty); ]W89.><%14
Y}eZPG.h
;igEIGR
InputStream input = httpConnection.getInputStream(); >$d d9|[
//logResponseHead(httpConnection); J@=!w[v+
$`cy'ZaF
@B}&62T
byte[] b = new byte[1024]; Yb,G^+;
int nRead; W\d0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^XjvJa
{ j@kRv@
nStartPos += fileAccessI.write(b,0,nRead); EBN]>zz
//if(nThreadID == 1) BxW||O|_N"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =|DkD- O
} $i5G7b
s.k`];wo
_rWTw+ L
Utility.log("Thread " + nThreadID + " is over!"); (7 ]\p
bDownOver = true; {Tjtj@-
//nPos = fileAccessI.write (b,0,nRead); *X"F:7
} 2n"*)3Qj
catch(Exception e){e.printStackTrace ();} X.r!q1_c
} VLl&>Pbe-
} [U+<uZzOC
2/a04qA#
x_>"Rnv:K
//打印回应的头信息 see'!CjVo2
public void logResponseHead(HttpURLConnection con) "N=&4<]I5
{ :6HiP&<
for(int i=1;;i++) z^SN#v$
{ TLR Lng
String header=con.getHeaderFieldKey(i); ul]m>W
if(header!=null) $)WH^Ir~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d@`-!"
Utility.log(header+" : "+con.getHeaderField(header)); qrORP3D@
else <3J=;.\6
break; d-_93
} kG~ivB}x
} "X!_37kQ
-&HoR!af
"1pZzad
public void splitterStop() ZFd{q)qe
{ `rRg(fCN!M
bStop = true; g]TI8&tP!L
} fitK2d
[jmAMF<F
+L<w."WG
} 9h)P8B.>M
).@)t:uNa
!*$'fn'bAA
/* !Dhfr{
**FileAccess.java eQ4B5B%j/x
*//文件访问(定位，写) \t7zMp
package NetFox; +q>C}9s3
import java.io.*; & t@
x Ps&CyI
*jqPKK/
public class FileAccessI implements Serializable{ '!2
'j=PbA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9EY_R&Yq%
RandomAccessFile oSavedFile; >LRaIU>
long nPos; r>D[5B
]mDsUZf<
#|2g{7g*
public FileAccessI() throws IOException DrYoC7
{ 9Y*VzQE
this("",0); kA->xjk
} =V4_DJ(&
(Nve5
1QdB`8in
public FileAccessI(String sName,long nPos) throws IOException j4hUPL7
{ ,_7tRkn
oSavedFile = new RandomAccessFile(sName,"rw"); r+WPQ`Ar
this.nPos = nPos; [zO(V`S2
oSavedFile.seek(nPos); <\#
} ^SelqX
6!Ap;O^*
d+wNGN
public synchronized int write(byte[] b,int nStart,int nLen) Z6HkQ=A64
{ . KSr@Gz
int n = -1; (\[!,T"[
try{ EEnTq
oSavedFile.write(b,nStart,nLen); $f@-3/V6{
n = nLen; 0yEyt7 ~@
} )a2m<"
catch(IOException e) GA*Khqdid
{ & ;x1Rx
e.printStackTrace (); &|,qsDK(
} OEqe^``!
97@?QI}
`Rub"zM
return n; +AhR7R!
} T;XEU%:LK
@s}I_@
QZ$94XLI
} BC ]^BKP
A,ttn5Sh?
^0_*AwIcN
/* bg[k8*.:F
**SiteInfoBean.java 'Cd8l#z7
*/ =;-/( C
package NetFox; `re]Q0IO
@vh3S+=M
\$}xt`6p
public class SiteInfoBean { OD-CU8X9
B q+RFo
^n!{ vHz
private String sSiteURL; //Site's URL iJv4%|9
private String sFilePath; //Saved File's Path b#(SDNo6
private String sFileName; //Saved File's Name iT1"Le/N
private int nSplitter; //Count of Splited Downloading File c[}h( jkP
C'4u+raq
B$1nq#@
public SiteInfoBean() 1k6f|Al-
{//nSplitter的缺省值为5 Wp/!;
//default value of nSplitter is 5 H0Qpc<Z4/
this("","","",5); R/R[r> 1)6
} \[Op:^S
Vy.A`Hz
gV1&b (h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4-^|e
{ ;2q;RT`h
sSiteURL= sURL; M p:c.
sFilePath = sPath; M8X*fYn
sFileName = sName; /tM<ois*
this.nSplitter = nSpiltter; K++pH~o
4Z)`kS}=]
$6}siU7s4
} EGO;g^,
)_"Cz".|9
UeV2`zIg`
public String getSSiteURL() D-\\L[
{ mVfg+d(
return sSiteURL; ]|18tVXc
} 4j|]=58
+8Yt91
1fM=>Z
public void setSSiteURL(String value) z)xGZ*{=
{ H$au02dpU
sSiteURL = value; ks<gSCB
} 4SCb9|/Q
]IMBRZQqb
fqZqPcT0
public String getSFilePath() hAi50q;z
{ )[yM4QFl
return sFilePath; u6IEBYG ((
} \!j{&cJ
S9d+#6rn
gm~Ka%O|F
public void setSFilePath(String value) NX&mEz
{ (`x6QiG!
sFilePath = value; ZfM(%rx
} y5B4t6M(
v/=O:SM}
G 5w:
public String getSFileName() QE[ETv
{ 6DqV1'
return sFileName; &MsnQP
} V^B'T]s
U4qp?g+:
L$6{{Tw"2
public void setSFileName(String value) :$."x '
{ Ar7vEa81
sFileName = value; L^3~gZ
} ,u7:l
!q=ej^(S
%myg67u
public int getNSplitter() x9XQ
{ u'M\m7
return nSplitter; |K| c
} s<Pk[7`*
]n1@!qa48
^dFdw\
public void setNSplitter(int nCount) ag^EH"%zw
{ r7o63]
nSplitter = nCount; G/>upnA{w
} Zc(uK{3W-
} wG6>.`:
hd1(q33
Z12-Vps
/* w^EAk(77
**Utility.java 0FD#9r
*/ 4CVtXi_Y
package NetFox; ?RJ )u
pt<!b0G
&Q 7Q1`S
public class Utility { +pp|Qgr 3
=UYZ){rt9E
v?BX 4FO
public Utility() hZf0q 2
{ (@@t,\iF
S"0<`{Gv
3<sYxA\?w
} IOmQ1X7,
Q$Qs$
//线程睡眠 VCfa<hn
public static void sleep(int nSecond) U|VFzpJ
{ 2Sbo7e
try{ B'"(qzE-kM
Thread.sleep(nSecond); T#%r\f,l0
} Y ]&D;w
catch(Exception e) swV/Mi>
{ {^zieP!
e.printStackTrace (); Y5e6|b|
} D_er(
} rKg~H=4x2
.si!`?K%[
//日志 0J7)UqMf.
public static void log(String sMsg) ,pL%,>R5
{ >5-z"f
System.err.println(sMsg); G6wBZ?)k
} !j[Oyr|
Bc3(xI'>J
|2w,Np-
public static void log(int sMsg) ,?g}->ZB
{ HLm6BtE
System.err.println(sMsg); ]FV,}EZ
} 6cH.s+
} &6 .r=,BO
gz8>uGx&V!
`Mx&,;x
/* at"-X?`d
**TestMethod.java e]F4w(*=
*/ ZdG?fWWA
package NetFox; .`qw8e}y#'
x&>zD0\ :\
Q${0(#Nu
public class TestMethod { =yo?]ZS
\`3YE~7J/
"cSH[/
public TestMethod() V ':?rEN|
{ ///xx/weblogic60b2_win.exe zzOc # /
try{ yg34b}m{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B>sSl1opI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yneIY-g(p
SiteFileFetch fileFetch = new SiteFileFetch(bean); 40,u(4.m*
fileFetch.start(); k\(LBZ"vR
} pJ)PVo\cV
catch(Exception e){e.printStackTrace ();} b.HfxYt(
}4G/x;D
O6JH)Ka"S
} j"g[qF/*
NKyaR_q`
O#Y;s;)i"
public static void main(String[] args) <sdC#j
{ 17IT:T,'
new TestMethod(); oAaUXkQE
} e(nT2E
} #+$pE@u7A
点击下载更多相关资料