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)); '#=0q
} %V+"i_{m
for(int i=0;i<nEndPos.length-1;i++) - Ry+WS=
{ ;<_a ,5\Q
nEndPos = nStartPos[i+1]; r)OiiD"
} -/V(Z+dj
nEndPos[nEndPos.length-1] = nFileLength; u0A$}r$L
} 2dcvB]T!
} .FC+
ifu!6_b.
!zllvtK4
//启动子线程 ,aa 4Kh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h(<>s#=E
for(int i=0;i<nStartPos.length;i++) {+nf&5E 6
{ '5LdiSk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2ij&Db/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Dh}(B$~Oz+
nStartPos,nEndPos,i); R PoBF~>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j>B*8*Ss
fileSplitterFetch.start(); 0{vH.b @
} AI Kz]J0;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |xg_z&dX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =5Nh}o(l?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O ;[Mi
nEndPos = " + nFileLength); GM?s8yZ<
// fileSplitterFetch[nPos.length-1].start(); aKWxLe
^g5E&0a`g
k!}(a0h
//等待子线程结束 8A.7q
//int count = 0; EmR82^_:
//是否结束while循环 d~QM@<SV
boolean breakWhile = false; w;j<$<4=7
>TY;l3ew
x^EW'-a
while(!bStop) 74MxU
{ m#Z&05^
write_nPos(); ;+(VO
Utility.sleep(500); q6w)zTpJGJ
breakWhile = true; ~J&-~<%P}
;{L[1OP%e
`:*2TLxIk
for(int i=0;i<nStartPos.length;i++) 4(LLRzzW
{ 6/5,n0
if(!fileSplitterFetch.bDownOver) BgQ/$,
{ J?yasjjgP
breakWhile = false; M<d!j I9)
break; 0<a|=kZ
} 2l+L96
} )#cZ& O
if(breakWhile) nq8XVT.m^\
break; ()bQmNqmO=
2#sFY/@
[DH4iG5
//count++; $ P5K
//if(count>4) Pd\4hy
// siteStop(); Fa[^D~$l*
} <kPNe>-f
ZTV)D
t!*[nfR
System.err.println("文件下载结束！"); 1n[)({OQ
} Mms|jFoQ
catch(Exception e){e.printStackTrace ();} vxTn
} _:=\h5}8
HbI{Xf[6LP
6V%}2YE?X
//获得文件长度 vt2. i$u
public long getFileSize() G<D8a2q
{ hTzj{}w
int nFileLength = -1; \<*F#3U1
try{ (${ #l
URL url = new URL(siteInfoBean.getSSiteURL()); &K[sb%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *$BUow/>
httpConnection.setRequestProperty("User-Agent","NetFox"); [n)ak)_/
cx$h"
kSzap+nB?
int responseCode=httpConnection.getResponseCode(); GEF's#YWK
if(responseCode>=400) j?m(l,YD|*
{ yRyXlZC
processErrorCode(responseCode); vj%"x/TP
return -2; //-2 represent access is error #e-K It
} QK[^G6TI
$f0u
o>C,Db~L/
String sHeader; 2HmK['(
m~AAO{\:b
V [g^R*b
for(int i=1;;i++) j8p<HE51
{ k>mXh{(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (ct1i>g
//Utility.log(in.readLine()); os"R'GYmf
sHeader=httpConnection.getHeaderFieldKey(i); Qe>_\-f
if(sHeader!=null) Ye&/O<G'V
{ \-pwA j?
if(sHeader.equals("Content-Length")) L?+N:G
{ g;'S5w9S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H=C~h\me?
break; x-k-Pd
} h~\k;ca
} hdx_Tduue
else 9 da=q
break; (WC =om
} [mu8V+8@d4
} tj~r>SRb+
catch(IOException e){e.printStackTrace ();} pNOE KiJ
catch(Exception e){e.printStackTrace ();} ~6n|GxR.[
PiM(QR
i@nRZ$K
Utility.log(nFileLength); 2|lR@L sr
zPp22
N^$q;%
return nFileLength; bWp:!w#K
} W,6q1
iv_3R}IbX
JI]Lz1i
//保存下载信息（文件指针位置） f&4+-w.:V|
private void write_nPos() y EfAa6
{ s(3u\#P
try{ m_oUl(pk
output = new DataOutputStream(new FileOutputStream(tmpFile)); _Sfu8k>):
output.writeInt(nStartPos.length); ~6kF`}5
for(int i=0;i<nStartPos.length;i++) n'^`;-
{ |.$B,cEd
// output.writeLong(nPos); F$tzsz,9n
output.writeLong(fileSplitterFetch.nStartPos); Nuot[1kS
output.writeLong(fileSplitterFetch.nEndPos); ;&=CZ6vH
} 8|)!E`TKSV
output.close(); g$Y]{VM.J
} z0/+P
catch(IOException e){e.printStackTrace ();} Z40k>t D
catch(Exception e){e.printStackTrace ();} _lkVT']
} 0SYJ*7lPX
S?JCi=
KPO w
//读取保存的下载信息（文件指针位置） /kG?I_z
private void read_nPos() -c?x5/@3
{ onSt%5{P%X
try{ ?wG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i /[{xRXiR
int nCount = input.readInt(); ,Ohhl`q(
nStartPos = new long[nCount]; `)y ;7%-
nEndPos = new long[nCount]; V[kJ;YLPN
for(int i=0;i<nStartPos.length;i++) @NA+Ma{N
{ vc|tp_M67
nStartPos = input.readLong(); W vB]Rs
nEndPos = input.readLong(); g]L8Jli
} }C_g;7*
input.close(); f\cTd/?Ju
} 1$03:ve1
catch(IOException e){e.printStackTrace ();} J' P:SC1
catch(Exception e){e.printStackTrace ();} ^2$b8]q
} YU-wE';H6
TxK v!-1
~3j+hN8<
private void processErrorCode(int nErrorCode) oCOv 6(
{ J&~I4ko]
System.err.println("Error Code : " + nErrorCode); 4'#=_J
} ^2Cqy%x-
9D\E0YG X/
G`%rnu
//停止文件下载 @JhkUGG]p
public void siteStop() )J@[8 x`
{ uo]\L^j
bStop = true; IrCl\HQN
for(int i=0;i<nStartPos.length;i++) =@4,szLO
fileSplitterFetch.splitterStop(); _@XueNU1hS
yOlVS@7
]@z!r2[
} PU.j(0
} &2 Yo
//负责部分文件的抓取 H4 O"^#5
**FileSplitterFetch.java jbS@6 *_
*/ h/\Zq
package NetFox; q[qX O5
8BAe6-*S8
Zc_F"KJL
import java.io.*; 6/wC StZ
import java.net.*; Kn$E{F\
<`SA>P
83V\O_7j
public class FileSplitterFetch extends Thread { Vbp@n
}|Q\@3&
n%36a(] t
String sURL; //File URL <(Ar[Rp
long nStartPos; //File Snippet Start Position U~yPQ8jD
long nEndPos; //File Snippet End Position 5g-1pzP9
int nThreadID; //Thread's ID ],!}&#|
boolean bDownOver = false; //Downing is over h& 4#5{=
boolean bStop = false; //Stop identical ZKt{3P
FileAccessI fileAccessI = null; //File Access interface cLL2 '
h#UPU7;
+76ao7d.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?H_@/?
{ D]iyr>V6'
this.sURL = sURL; V_$<^z|
this.nStartPos = nStart; '>|Kd{J0
this.nEndPos = nEnd; 09vVCM;DY
nThreadID = id; ckFPx l.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >?JUGXAi'{
} KS5a8'U
zwQ#Yvd
<Af&Q0J
public void run() ] rqx><!
{ ~P}ng{x4z
while(nStartPos < nEndPos && !bStop) 6rE8P#
{ TW1`{SM
s7}-j2riq
\anOOn@
try{ 3%9XJ]Qao
URL url = new URL(sURL); M<l<n$rYS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eVMnI yr
httpConnection.setRequestProperty("User-Agent","NetFox"); ]:F!h2
String sProperty = "bytes="+nStartPos+"-"; ZZkc) @
httpConnection.setRequestProperty("RANGE",sProperty); DS4y@,/)'
Utility.log(sProperty); bydI+pVMo
Q1kM 4Up
e9'0CH<
InputStream input = httpConnection.getInputStream(); DQu)?Rsk
//logResponseHead(httpConnection); Zp{K_ec{
Xajt][
0[YksNNl1
byte[] b = new byte[1024]; +pK35u
int nRead; EFtn!T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) //r)dN^
{ s."N7F
nStartPos += fileAccessI.write(b,0,nRead); b~<V}tJ
//if(nThreadID == 1) X<Xiva85
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WaX!y$/z
} Dby|l#X
\uo{I~Qd
Ed0}$b
Utility.log("Thread " + nThreadID + " is over!"); nZYO}bv\
bDownOver = true; j7I?K :op=
//nPos = fileAccessI.write (b,0,nRead); kene' aDm
} @>ys,dy
catch(Exception e){e.printStackTrace ();} k&[6Ld0~56
} W"\`UzOLQ
} T%"wz3~
?)<zzL",
2Gj)fMK38
//打印回应的头信息 ^u90N>Dvq
public void logResponseHead(HttpURLConnection con) q3v5gz^t
{ ntPX?/
for(int i=1;;i++) N2j^fZd_
{ +>yh`Zb
String header=con.getHeaderFieldKey(i); yoieWnL}
if(header!=null) <7Yh<(R e^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); keQRS+9
Utility.log(header+" : "+con.getHeaderField(header)); t<}N>%ZO
else k=p[Mlic/
break; t5 ^hZZ
} !YO'u'4<aK
} Mg}/gO%o
gE*7[*2?t
}=|{"C
public void splitterStop() /VEK<.,aMv
{ Y HS/|-
bStop = true; yZoJD{'?Sw
} }[c.OJ:
ZhRdml4U2
iM1E**WCtv
} g^po$%I '
k MV1$
OM7AK B=S
/* fV6ddh
**FileAccess.java 7#Fcn
*//文件访问(定位，写) e=#D1
package NetFox; lc [)Ev
import java.io.*; p,(W?.ZDN?
XN\rq=
#Rs5W
public class FileAccessI implements Serializable{ .*+jD^Gr
T~XKV`LQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {{pN7Z
RandomAccessFile oSavedFile; y= 8SD7P'
long nPos; `d/* sX?k
(6}7z+
:1"k`AG
public FileAccessI() throws IOException e:N;Jx#
{ W"t^t|H'~
this("",0); b>#dMRK
} ;/ |tU o$
Y>8JHoV
8090+ (U
public FileAccessI(String sName,long nPos) throws IOException IZQ*D)
{ {7$jwk
oSavedFile = new RandomAccessFile(sName,"rw"); |,H2ge
this.nPos = nPos; @a=jSB#B
oSavedFile.seek(nPos); qrZ3`@C4k
} d|W=_7z
,E%O_:}R
@S5HMJ2=
public synchronized int write(byte[] b,int nStart,int nLen) *].qm g%
{ j]-_kjt
int n = -1; >-3>Rjo>
try{ -V"W
oSavedFile.write(b,nStart,nLen); |v#D}E
n = nLen; !N][W#:
} UbIUc}ge
catch(IOException e) k3Puq1H
{ @li/Y6Wh
e.printStackTrace (); R7h3O0@!
} /74h+.amg
ru1^.(W2
A|U0e`Iw
return n; OP=-fX|*Q
} Q$k#q<+0
B o%Sl
SY@;u<Pd
} 3U!=R-
c7[Ba\Cr4h
zR/mz)6_
/* xBf->o S?
**SiteInfoBean.java U1rr=h g
*/ ^;[_CF_
package NetFox; $Tt.r
@W==)S%O
:>H{?
public class SiteInfoBean { ug"4P.wI
MpJ\4D5G
kaIns
private String sSiteURL; //Site's URL \PG_i'R
private String sFilePath; //Saved File's Path c&h8Qk3
private String sFileName; //Saved File's Name YuJ{@"H
private int nSplitter; //Count of Splited Downloading File (4C)] RHQ
E]a;Ydf~
q]Xu #:X
public SiteInfoBean() 6p3cMJ'8y
{//nSplitter的缺省值为5 Y;E'gP-J
//default value of nSplitter is 5 xh25 *y
this("","","",5); i],~tT|P
} uz20pun4B
O@dK^o
bTAY5\wB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,C_MB1u
{ ,K30.E
sSiteURL= sURL; w?M"`O(
sFilePath = sPath; &5B/>ag1!
sFileName = sName; Are0Nj&?
this.nSplitter = nSpiltter; \CS4aIp
j+gh*\:q
xbHI4A"Z
} X%B$*y5
e5;YY
+br' 2Pn
public String getSSiteURL() FlrYXau
{ #e@[{s7
return sSiteURL; 5'w&M{{9
} i3$G)W
+t Prqv"(
c]$$ap
public void setSSiteURL(String value) J{XRltI+
{ I1K%n'D
sSiteURL = value; F/:%YR;
} ?zVE7;r4U
D)S_ p&
;/IXw>O(/
public String getSFilePath() VuK>lY&
{ 0r!F]Rm-^
return sFilePath; p`52
} IEkbVIA(
PB BJ.!Pb
CU*;>h1~u
public void setSFilePath(String value) } ,Dk6w$
{ 9Gx`[{wI9<
sFilePath = value; ['iEw!
} N1x~-2(
i2[8^o`_
,&* BhUC
public String getSFileName() YOvhMi
{ 2jkma :$'
return sFileName; ?T|0"|\"'
} cqm:[0Xf5>
jj 'epbA
=k1sF3.V'c
public void setSFileName(String value) ']1a
{ GI:!,9
sFileName = value; Vk[M .=J
} z XUr34jF
@s,kx.S
;!3: 3;
public int getNSplitter() P1$D[aF9$
{ X_,R!$wbg:
return nSplitter; |S:erYE,G
} GE!p
W}%[i+
6%wlz%Fp
public void setNSplitter(int nCount) "t-9q
{ u6MU @?
nSplitter = nCount; )?6%d
} ={o)82LV
} lB#7j
rc"8N<D
WHUl.h
/* S&J5QZjC
**Utility.java j|XL$Q
*/ -q?,
package NetFox; ]kO|kIs
VAqZ`y
BV}sN{
public class Utility { TWfkr
Ya!PV&"Z
'tX}6wurf
public Utility() mSk";UCn
{ ]U}B~Y
q:vGGK^
wZKmU
} f*p=j(sF
,;<M+V3+
//线程睡眠 HJlxpX$_
public static void sleep(int nSecond) HLc3KYIk
{ D^f;X.Qm
try{ ,,7hVw
Thread.sleep(nSecond); j}fSz)`i
} rQ&XHG>Q*
catch(Exception e) m5,&;~
{ OE_V6Er
e.printStackTrace (); Zv8_<>e
} ?H_>?,^
} \pP1k.~UnC
GBT219Z@8
//日志 6X!jNh$oF
public static void log(String sMsg) 152LdZevF
{ 2|NQ5OA0
System.err.println(sMsg); Oa M~rze
} b8Hzl!zO
@,LU!#y(
I\IDt~
public static void log(int sMsg) FiXqypT_(
{ F4ylD5Y!
System.err.println(sMsg); x<.(fRv
} jBd=!4n
} ,)VAKrSg
{j4&'=C:
JcfGe4
/* !:}m-iqQ1
**TestMethod.java XdnpL$0
*/ TJZarNc$
package NetFox; G6xNR
]]y,FQ,r
2av=W
public class TestMethod { c}H}fyu%n
z<J2e^j
[lu+"V,<LJ
public TestMethod() X}ihYM3y/
{ ///xx/weblogic60b2_win.exe YHxQb$v)
try{ Mq#Hi9SKY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {CFy %
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xZ SDA8kS
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Z52L`k
fileFetch.start(); }VHvC"
} `\/\C[Gg
catch(Exception e){e.printStackTrace ();} 0;]VTz?P
ZoCk]hk
+6^hp-G7
} 6 B7F
R0bgt2J
]3Jb$Q@
public static void main(String[] args) C^:{y
{ ~4xn^.w
new TestMethod(); ,|j\x
} $I<\Yuy-M9
} r"t,/@`n
点击下载更多相关资料