http断点续传简单实现（java)

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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)); P!j*4t
} ]C+PJ:CC
for(int i=0;i<nEndPos.length-1;i++) kuLur)^
{ 2YQBw,gG
nEndPos = nStartPos[i+1]; 5i{J0/'Xu)
} sm[zE/2b
nEndPos[nEndPos.length-1] = nFileLength; @o}J)
} <o|k'Y(-
} YsiH=x
dKXzFyW
J?t(TW6E
//启动子线程 ow`F 7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9T$%^H9
for(int i=0;i<nStartPos.length;i++) WSU/Z[\`H
{ c;t3I},
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q9p7{^m&E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {#@[ttw$U
nStartPos,nEndPos,i); ~z41$~/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1S+T:n
fileSplitterFetch.start(); rK;<-RE<[:
} RxPD44jVA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J.g6<n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q>\DM'{:4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d7&d FvG
nEndPos = " + nFileLength); Ps0<CUyI
// fileSplitterFetch[nPos.length-1].start(); eLHhfu;k
M $EHx[*5
HpeU'0u0VK
//等待子线程结束 kDR5kDiS
//int count = 0; y fuH
//是否结束while循环 it>l?h7I
boolean breakWhile = false; ~EQ# %db
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j+lcj&V#
while(!bStop) |Q%nnN
{ f/.f08
write_nPos(); !)J$f_88D
Utility.sleep(500); FL$S_JAw
breakWhile = true; 1B 0[dK2N
n#?y;Y\
+uNMyVH
for(int i=0;i<nStartPos.length;i++) p? VDBAx
{ wJgH15oB
if(!fileSplitterFetch.bDownOver) +>Y]1IlI
{ #4nBov3d
breakWhile = false; e!w{ap8u
break; tk 5p@l
} .k up[d(
} Y)GU{
if(breakWhile) 5YI6$ZdQ
break; L"T :#>
eAQ-r\h'2
Z)3oiLmD
//count++; |hDN$By
//if(count>4) FKf2Q&2I
// siteStop(); x>4p6H{]0'
} 3RlNEc%)
ZRr.kN+F
]haQ#e}WH
System.err.println("文件下载结束！"); mZ?QtyljT
} vQoZk,
catch(Exception e){e.printStackTrace ();} 931GJA~g
} r4?|sAK
pma=*
R$eEW"]
//获得文件长度 7coVl$_Zl
public long getFileSize() zqXDD; w3
{ r#}o +3*
int nFileLength = -1; HYJEz2RF
try{ O ~[[JAi[
URL url = new URL(siteInfoBean.getSSiteURL()); _3g!_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "-IF_Hid
httpConnection.setRequestProperty("User-Agent","NetFox"); .%0a
olHmRJ
NQOf\.#g
int responseCode=httpConnection.getResponseCode(); j(pe6
if(responseCode>=400) Lo)T
{ h]Gvt 5
processErrorCode(responseCode); egWfKL&iy
return -2; //-2 represent access is error Kb/qM}jS
} $(yi+v
rNke&z:%X_
@!!5el {
String sHeader; Smh=Q4,W
$p}q,f.
E;k$ICOXA
for(int i=1;;i++) }1a(*s,s-^
{ XZTH[#MqeI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KfC{/J\
//Utility.log(in.readLine()); mZnsr@KF
sHeader=httpConnection.getHeaderFieldKey(i); >V%.=})K
if(sHeader!=null) NXS$w{^
{ h>z5m
if(sHeader.equals("Content-Length")) P+e{,~o
{ )2jH&}K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wr>6Go%
break; 'OU3-K
} :$XlYJrjK
} -<u_fv
else gEgd/Le
break; 5RF*c,cNq
} BISH34
} =""5 c
catch(IOException e){e.printStackTrace ();} je>mAQKi\
catch(Exception e){e.printStackTrace ();} G}]'}FUp
[xdVuL;N
+mO/9m
Utility.log(nFileLength); M@pF[J/
4jVd
3]&le[.
return nFileLength; <c,iu{:
} ?. L]QU
}Os7[4RW
@JJ{\?>
//保存下载信息（文件指针位置） ,s,AkH
private void write_nPos() [_C([o'\KY
{ Ubwmn!~
try{ w[^lxq
output = new DataOutputStream(new FileOutputStream(tmpFile)); `0u)/s$
output.writeInt(nStartPos.length); 530Kk<%^}8
for(int i=0;i<nStartPos.length;i++) S} &1_I
{ BG1hk!
// output.writeLong(nPos); MTbCL53!-
output.writeLong(fileSplitterFetch.nStartPos); y8v0>V0)
output.writeLong(fileSplitterFetch.nEndPos); kWCxc0
} h6:|RGF
output.close(); BGstf4v>A<
} P;IM -]
catch(IOException e){e.printStackTrace ();} l5enlYH
catch(Exception e){e.printStackTrace ();} k/Q8:qA
} sv!6zJs
[|C
*M$$%G(4
//读取保存的下载信息（文件指针位置） E7<l^/<2S+
private void read_nPos() 9SU/86|N
{ &~=d;llkT
try{ LO%OH u}]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _akpW
int nCount = input.readInt(); BMn`t@!x
nStartPos = new long[nCount]; , LqfwA|
nEndPos = new long[nCount]; pA\"Xe&
for(int i=0;i<nStartPos.length;i++) L*{E-m/
{ Yg;7TKy
nStartPos = input.readLong(); ;;432^jD
nEndPos = input.readLong(); $o ;48uV^
} J[\8:qE
input.close(); qMd4awB R
} @A-E
catch(IOException e){e.printStackTrace ();} Saks~m7,
catch(Exception e){e.printStackTrace ();} QC1\Sn/
} 0"mr*hyj
]];LA!n
IKp/xj[!
private void processErrorCode(int nErrorCode) T4;gF6(0]
{ 78IY&q:v&0
System.err.println("Error Code : " + nErrorCode); ]1q`N7
} \.=,}sV2Z
"~08<+
c$;Cpt@-j
//停止文件下载 byk9"QeY\
public void siteStop() {@t6[g++
{ 0.^67'
bStop = true; q9nQ/]rkHF
for(int i=0;i<nStartPos.length;i++) MX|@x~9W
fileSplitterFetch.splitterStop(); _u#r;h[
VexQ ]
(%4O\s#l
} -]:1zU
} r <2&_$|
//负责部分文件的抓取 l~x 6R~q
**FileSplitterFetch.java E/C3t2@-
*/ \"+}-!wr
package NetFox; 8?hj}}H
YG#{/;^nm)
cM=_i{c
import java.io.*; Ge*N%=MX8
import java.net.*; "l(<<Ha/
cu4|!s`#
3nx*M=
public class FileSplitterFetch extends Thread { 58PL@H~@0
yDi'@Z9R?
Co:Rg@i(F
String sURL; //File URL r<$"T
long nStartPos; //File Snippet Start Position ;4*mUD6
long nEndPos; //File Snippet End Position lt{"N'Gw6
int nThreadID; //Thread's ID S\@U3|Q5
boolean bDownOver = false; //Downing is over xHlO~:Lc
boolean bStop = false; //Stop identical X D\;|
FileAccessI fileAccessI = null; //File Access interface q)RTy|NJ^
%)y-BdSp.
`OWwqLoeA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %eJE@$
{ vZ|Wj] ;o
this.sURL = sURL; 0w6"p>s>c
this.nStartPos = nStart; 2-rfFqpe
this.nEndPos = nEnd; |1m2h]];Q
nThreadID = id; xp]_>WGq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -g4 {:!*D
} W'Y#(N[ktP
&hIr@Gi@ch
-8sB\E
public void run() _TVKvRh
{ 'c$)}R I7
while(nStartPos < nEndPos && !bStop) Ne}x(uRn
{ mzn#4;m$
T{lK$j
O/fm/
try{ er2#h
URL url = new URL(sURL); vgKdhN2kI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >2#F5c67
httpConnection.setRequestProperty("User-Agent","NetFox"); v<gve<]
String sProperty = "bytes="+nStartPos+"-"; BBj>ML\X
httpConnection.setRequestProperty("RANGE",sProperty); 69zMWuY
Utility.log(sProperty); w[/m:R?eX
^dKtUH/78G
lR5k1J1n
InputStream input = httpConnection.getInputStream(); 'CvV Ktk
//logResponseHead(httpConnection); E7@m& R
B\quXE)
1j!{?t?
byte[] b = new byte[1024]; uL=FK
int nRead; k}e~xbh-y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sE\Cv2Gx
{ Tuy5h5
nStartPos += fileAccessI.write(b,0,nRead); OJ<V<=MYZ
//if(nThreadID == 1) l'Uj"9r,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {\n?IGP?wd
} uiaZ@
g 4lk
p9~$}!ua
Utility.log("Thread " + nThreadID + " is over!"); }%S#d&wh$_
bDownOver = true; w!52DBOe+
//nPos = fileAccessI.write (b,0,nRead); ]U.*KkQ
} _O`s;oc
catch(Exception e){e.printStackTrace ();} '-rRD\"q
} P u,JR
} +?GsIp@>jh
rpv<'$6
byX)4&
//打印回应的头信息 e0`5PVJ
public void logResponseHead(HttpURLConnection con) Vv*](iM
{ Gg5+Ap D
for(int i=1;;i++) Z<[:v2
{ f SMy?8
String header=con.getHeaderFieldKey(i); dEPLkv
if(header!=null) x+W,P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^8 cq qu
Utility.log(header+" : "+con.getHeaderField(header)); ulNMqz\.
else J,t`ilT
break; Lwkl*
} SF[}suL
} :[ll$5E.
J{PNB{v
fmv,)UP
public void splitterStop() =8Gpov1!V~
{ c6MMI]+8
bStop = true; ;AJ6I*O@+
} x]~&4fp
=v=u+nO
U,Z7nH3_
} p4z thdN[
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sQMfU{S /
/* ,(z"s8N
**FileAccess.java h|OWtf4
*//文件访问(定位，写) `"y:/F"{
package NetFox; M^.>UZKyl
import java.io.*; lF3wTf/j
mIv}%hD
|eP5iy wg
public class FileAccessI implements Serializable{ g\G}b
xi15B5_Ps
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !Mj28
RandomAccessFile oSavedFile; 3% O[W
long nPos; Fq'Ds[wd5
{Hzj(c~S?
"$A5:1;
public FileAccessI() throws IOException -mG ,_}F
{ z(1`Iy M
this("",0); |F&02f!]@
} pSodTG$E
=&WH9IKz
-b=Aj8h
public FileAccessI(String sName,long nPos) throws IOException m`Pk)c0
{ )&93YrHgC
oSavedFile = new RandomAccessFile(sName,"rw"); v>0} v)<v
this.nPos = nPos; wx_j)Wij6
oSavedFile.seek(nPos); - 9a4ej5
} G$;cA:p-j
KxQMPtHstz
o~26<Lk
public synchronized int write(byte[] b,int nStart,int nLen) ^n*:zmD
{ c uHF^l
int n = -1; ^#4Ah[:XA
try{ Oe lf^&m
oSavedFile.write(b,nStart,nLen); <yw56{w,
n = nLen; XCyrr2^
} zEi\#Zg$
catch(IOException e) gB]jLe
{ @]dv
e.printStackTrace (); I !O5+Er
} |cL,$G
)Kq@ m1>@
,91n
return n; I6PReVIb
} qD,/Qu62
Dw<bLSaW&
D_ XOYzN}
} sCE%./h]
g1)ZjABV
~%@1-
/* >~L0M
**SiteInfoBean.java SZ~lCdWad
*/ ;KT/;I
package NetFox; 8LUl@!4b
JV?d/[u,
':]Hj8t_
public class SiteInfoBean { M"yOWD~s~
o,{]<Sm
me$nP}%C&
private String sSiteURL; //Site's URL 'u6n,yRm
private String sFilePath; //Saved File's Path a&u!KAQ
private String sFileName; //Saved File's Name %uvA3N>
private int nSplitter; //Count of Splited Downloading File $f+cd8j?o
2Q;rSe._`
C=JS]2W2
public SiteInfoBean() x|)pZa
{//nSplitter的缺省值为5 A[uB)wWsn
//default value of nSplitter is 5 Jv?EV,S/e
this("","","",5); S{N=9934_
} Ey{p;;H
SNSHX2
gi$'x^]#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #x \YA#~
{ 2x~Pq_?y
sSiteURL= sURL; vb3hDy
sFilePath = sPath; 8WC_CAP
sFileName = sName; 0bteI*L
this.nSplitter = nSpiltter; ZtY?X- 4_
~Gl5O`w(
d '\^S}
} ahFK^ #s
v ,zD52
15d'/f
public String getSSiteURL() ]d.e(yCuE
{ (6&"(}Pai
return sSiteURL; O)D$UG\<
} Xh}G=1}
6VLo4bq 5
,h<xY>
public void setSSiteURL(String value) pUa\YO1J
{ yatZAl(B
sSiteURL = value; M5 ^qc
} Nw1Bn~yx<R
3AAciMq}
`nY.&YT
public String getSFilePath() >X*Y jv:r
{ \{v-Xe&d^
return sFilePath; lv+: `
} Adgfo)X5
^DVryeLD
e$E>6Ngsr
public void setSFilePath(String value) jwSPLq%
{ p-H}NQ\
sFilePath = value; T[MDjhv'
} tToP7q^
\UZ7_\
O`T_'.Lk
public String getSFileName() ^fmuBe}d{
{ $i1:--~2\
return sFileName; 4gZ)9ya
} fNBI!=
wCu!dxT|,
rPt
public void setSFileName(String value) PsOq-
{ }zqo<o
sFileName = value; 4BeHj~~
} k{U[ U1j
N%%trlDXD
Lcf?VV}
public int getNSplitter() U2CC#,b!(
{ 8fktk?|
return nSplitter; q/ (h{cq
} x+b.9f4xJ
VCwC$ts
Yv0y8Vz@
public void setNSplitter(int nCount) ?Ezy0>j
{ wN^^_
nSplitter = nCount; x,|fblQz
} trB-(B%5
} VF g(:
|9X2AS Qu
G ]uz$V6!
/* 0.2stBw
**Utility.java \:+ NVIN
*/ dI>cPqQ
package NetFox; [f}`reRlZ
WD! " $
D1@yW} 4
public class Utility { C|[x],JCS
bZ^'_OOn
&Pc.[k
public Utility() 1hzf+*g
{ b"nkF\P@Fj
I zVc
y]+[o1]-c
} MWK)Bn
<4~SFTWY
//线程睡眠 sB$"mJ
public static void sleep(int nSecond) _!Pi+l4p/}
{ D7muf
try{ IiJ$Ng
Thread.sleep(nSecond); t=|}?lN<
} gZBKe!@a|
catch(Exception e) ]7oo`KcQ|
{ ?GqH/ (O
e.printStackTrace (); ydj*Jy'
} g^7zDU&'
} DtJ3`Jd
yE(<F2
//日志 f2&6NC;
public static void log(String sMsg) 5.DmMG[T^=
{ k8@bQ"#b
System.err.println(sMsg); xxr'g =
} \RRSrPLd-
pp(?rE$S
.J8 gW
public static void log(int sMsg) teC/Uf5
{ :Nwv&+
System.err.println(sMsg); ` N R,8F
} Q7{{r&|t&
} s,kY12<7m
aof'shS8
b5I 8jPj4c
/* gm=C0Sp?
**TestMethod.java wy{sS}
*/ ;PnN$g]Q
package NetFox; R3.w")6
f`_{SU"3
f9 :=6
public class TestMethod { /-t!)_zvw
a>9_#_hI
t o8J
public TestMethod() aQf2}kD
{ ///xx/weblogic60b2_win.exe lQ4^I^?m
try{ _MuzD&^qE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uXvE>VpJG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +$xw0)|
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7i'clB9!
fileFetch.start(); &4#%xg
} cIa`pU,6A
catch(Exception e){e.printStackTrace ();} tF 7u-
*5?Qam3
|T/s>OW
} @ &rf?:
-AU'1iRcK7
nEW.Y33
public static void main(String[] args) [*I7^h%
{ qn{4AWmJ
new TestMethod(); %s9*?6
} wZ69W$,p
} a/H5Y,b>
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