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)); cwU6}*_zn
} NPq2C8:
for(int i=0;i<nEndPos.length-1;i++) RaqrVC
{ ?Ir6*ZyY
nEndPos = nStartPos[i+1]; w5R9\<3L
} dQo$^?
nEndPos[nEndPos.length-1] = nFileLength; 2a}_|#*
} aa3YtNpP
} V:npcKpu
../(gG9
cW>`Z:6{K
//启动子线程 +eat,3Ji
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tjL#?j
for(int i=0;i<nStartPos.length;i++) y!Eh /KD
{ HM x9M$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sbb{VV`I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <m\TZQBD
nStartPos,nEndPos,i); 8;bOw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]vG)lY.=
fileSplitterFetch.start(); !"">'}E1
} Va:jMN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z}|'&O*.F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v7RDoO]I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", riQ?'!a7
nEndPos = " + nFileLength); ,s<d"]<
// fileSplitterFetch[nPos.length-1].start(); DenCD9 f
+d.Bf
H$HhB8z3
//等待子线程结束 /$Jh5Bv
//int count = 0; kSrzIq<xre
//是否结束while循环 $NSYQF%aO
boolean breakWhile = false; gnec#j
\^D`Hvg
m[rJFSpef
while(!bStop) ZGBcy}U(k
{ Z7/lFS'~N
write_nPos(); P^r8JhDJ
Utility.sleep(500); R2{X? 2|$
breakWhile = true; NH!!.Z"
Si(?+bda0c
MiI7s;
for(int i=0;i<nStartPos.length;i++) rA7S1)Kq
{ XPSWAp)
if(!fileSplitterFetch.bDownOver) ]y/:#^M+
{ ^ +G> N
breakWhile = false; [VHt#JuN,
break; KA7nncg;,
} mD:!"h/
} 2TO1i0
if(breakWhile) N[%IrN3
break; %\u>%s<9
-b<+Ra
_;9)^})$
//count++; .T2I]d
//if(count>4) 7UiU3SUcg
// siteStop(); j yE+?4w;
} ] N8V?.|:
y[# U/2
b?l\QMvi
System.err.println("文件下载结束！"); G}g+2`
} P^z)]K#sw
catch(Exception e){e.printStackTrace ();} x[E`2_Ff0
} f sMF46
x1Uj4*Au
+|N"i~f>j
//获得文件长度 ^"I!+Teb
public long getFileSize() wS*UXF&f
{ )!Bv8&;e
int nFileLength = -1; B7 T+a
try{ 6[i-Tl
URL url = new URL(siteInfoBean.getSSiteURL()); _~r>C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ay2.CBF
httpConnection.setRequestProperty("User-Agent","NetFox"); "xKJ?8
&e{&<ZVR
6mZFsB
int responseCode=httpConnection.getResponseCode(); %%#zO Z
if(responseCode>=400) k&*=:y}
{ IcN|e4t^J+
processErrorCode(responseCode); +Z+]Tqo
return -2; //-2 represent access is error D<:9pLD(
} P<U{jkM\/
nX~sVG{Q
)Fbkt(1
String sHeader; ?%?@?W>s@
;G?_^ 0
q~lmOT~E
for(int i=1;;i++) Q'Q^K
{ 6<2 7}S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VHy$\5oYg
//Utility.log(in.readLine()); %NKf@If)
sHeader=httpConnection.getHeaderFieldKey(i); m$3&r2vgi
if(sHeader!=null) (RQ kwu/
{ Pm-@ZZ~
if(sHeader.equals("Content-Length")) oY &r76
{ V`G]4}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =2< >dM#`
break; N(Cfv3{
} 6g)21Mh#
} EBJaFz'
else 2$|WXYY
break; /.vB /{2
} WVKzh
} =OCHV+m
catch(IOException e){e.printStackTrace ();} 1^vN?#Kt
catch(Exception e){e.printStackTrace ();} d+l@hgz~
i-$]Tg
(@]{=q<
Utility.log(nFileLength); wj5{f5 RWV
hC,EO&
">|fB&~A
return nFileLength; hl8[A-d(R
} $Z #
/S%{`F=
>%t"VpvR
//保存下载信息（文件指针位置） +as(m
private void write_nPos() 2!}5shB
{ 2 g,UdG
try{ //xxSk
output = new DataOutputStream(new FileOutputStream(tmpFile)); cZi/bIh
output.writeInt(nStartPos.length); K^>+"
for(int i=0;i<nStartPos.length;i++) t ?rUbN
{ jCkYzQUPz
// output.writeLong(nPos); &G:#7HX@-
output.writeLong(fileSplitterFetch.nStartPos); B\`4TU}kE
output.writeLong(fileSplitterFetch.nEndPos); +9M#-:qB
} _3.=| @L
output.close(); 7xqTTN6h
} (X;D.s
catch(IOException e){e.printStackTrace ();} !;>j(xc
catch(Exception e){e.printStackTrace ();} KFx4"f%
} zyTeF~_
l!5fuB8
w,n&K6<
//读取保存的下载信息（文件指针位置） {94qsVxQZ
private void read_nPos() 1?\G6T
{ Xgou7x<
try{ eT0Yp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %v5IR
int nCount = input.readInt(); 7b7@"Zw*
nStartPos = new long[nCount]; yz.a Z
nEndPos = new long[nCount]; $DBJ"8n2
for(int i=0;i<nStartPos.length;i++) >|IUjv2L
{ >NDI<9<'0}
nStartPos = input.readLong(); Gf*|f"O
nEndPos = input.readLong(); hj[&.w
} u 6A!Sw
input.close(); UDl[
} ,ELbm
catch(IOException e){e.printStackTrace ();} \iVb;7r)9:
catch(Exception e){e.printStackTrace ();} vr/*z euA
} O1[`2kj^HB
;hzm&My
M<$a OW0
private void processErrorCode(int nErrorCode) hhRUC&Y%V
{ -y]e`\+[
System.err.println("Error Code : " + nErrorCode); u4hC/!
} 4;_aFn
vf^`'
xO3-I@
//停止文件下载 f_'#wc6
public void siteStop() hUR>NUK@8
{ w8~B@}%
bStop = true; Qx<86aKkF
for(int i=0;i<nStartPos.length;i++) w`ebZa/j
fileSplitterFetch.splitterStop(); ?y"=jn
;l4epN
L{&5Ets
} mQwP-s
} LlbRr.wL
//负责部分文件的抓取 4}&$s
**FileSplitterFetch.java D6z*J?3^#&
*/ $1KvL8
package NetFox; cug=k
ey!QAEg"X1
I.'(n8*
import java.io.*; df9jT?l
import java.net.*; ~&{LMf
pd%h5|*n;
'fo.1
public class FileSplitterFetch extends Thread { ):<9j"Z;At
'TwvkU"
\+,%RN.
String sURL; //File URL 5|:t$
long nStartPos; //File Snippet Start Position 4 s&9A/&pC
long nEndPos; //File Snippet End Position $OGTHJA
int nThreadID; //Thread's ID s\/$`fuhx
boolean bDownOver = false; //Downing is over ` b$u w
boolean bStop = false; //Stop identical h_*!cuH
FileAccessI fileAccessI = null; //File Access interface }LYK:?_/
I)s~kA.e
KdN+$fe*g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v2K6y|6,
{ ?xX9o
this.sURL = sURL; nNj<!}HvV
this.nStartPos = nStart; *gGL5<%T:
this.nEndPos = nEnd; VelR8tjP
nThreadID = id; o!$O+%4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X7."hGu@
} i`st'\I
Z~[EZgIg
lJ>OuSd
public void run() n=_jmR1
{ ?hfyQhR
while(nStartPos < nEndPos && !bStop) QP?eKW9 :
{ S:F8`Gh
4arqlzlo
HEBKRpt
try{ jVdRy{MH
URL url = new URL(sURL); ?mq<#/qb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d$f3Cre
httpConnection.setRequestProperty("User-Agent","NetFox"); aWg*f*2f
String sProperty = "bytes="+nStartPos+"-"; Z4VNm1qs
httpConnection.setRequestProperty("RANGE",sProperty); md S`nhb
Utility.log(sProperty); r P1FM1"M
zLt7jxx
SN<Dxa8Iy
InputStream input = httpConnection.getInputStream(); u*"mdL2
//logResponseHead(httpConnection); J}?:\y<
QJ%[6S
-h%!#g
byte[] b = new byte[1024]; z\g6E/%%
int nRead; yb4Jsk5%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LFwRTY,G
{ $_5a1Lq1
nStartPos += fileAccessI.write(b,0,nRead); D^-6=@<3KD
//if(nThreadID == 1) SSrYFu"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u#bd*(
} 4+1aW BJ2
}eLnTi{
#)BbW40f6
Utility.log("Thread " + nThreadID + " is over!"); 5`tMHgQO
bDownOver = true; /\-iV)h1@
//nPos = fileAccessI.write (b,0,nRead); 'h*^;3@*
} .5AyB9a%&
catch(Exception e){e.printStackTrace ();} X}5}M+'~
} LkK# =v
} ;}W-9=81
!Zi_4 .(4
Z]^Ooy[pb
//打印回应的头信息 <$+Cd=71\
public void logResponseHead(HttpURLConnection con) =k0qj_
{ 'n$TJp|s
for(int i=1;;i++) ;;{!wA+"D
{ 0D.qc8/V4.
String header=con.getHeaderFieldKey(i); tqYwPSr
if(header!=null) :Sc"fG,g)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =[ZuE0c
Utility.log(header+" : "+con.getHeaderField(header)); i*l-w4D^U
else \2U FJ
break; _*1{fvv0{
} I[g;p8jr
} K.l7yBm
552yzn1
GYJ lX
public void splitterStop() &ZR}Z7E*=
{ V'Z Z4og
bStop = true; drkY~!a
} bw[s<z|LKA
*p !F+"
4n5r<?rY
} G9qN1q~
EmFL %++V
-:]-g:;/
/* =ICakh!TO
**FileAccess.java jMUN|(=Y
*//文件访问(定位，写) ~u^MRe|`
package NetFox; H="E#AC%8/
import java.io.*; *Y\C5L]
{wq~+O
[gE_\=FSKu
public class FileAccessI implements Serializable{ L5{DWm~@
")xd 'V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^f?>;,<&
RandomAccessFile oSavedFile; WETnrA"N
long nPos; %xuJQuCqf
'2=$pw
?BA~$|lfxu
public FileAccessI() throws IOException 9o<5Z=
{ /$Ca}>
this("",0); >u=Dc.lX
} tX'2 $}
dd6m/3uUW
tA{B~>
public FileAccessI(String sName,long nPos) throws IOException 8}_M1w6v
{ ymo].
oSavedFile = new RandomAccessFile(sName,"rw"); )Bo]+\2
this.nPos = nPos; J&w'0
oSavedFile.seek(nPos); 1Vi3/JM@
} D\CjR6DE
u+_6V
6aq=h`Y
public synchronized int write(byte[] b,int nStart,int nLen) JQ"R%g`8
{ g\~n5=-D
int n = -1; 8nKb mjM
try{ d:&=|kKw
oSavedFile.write(b,nStart,nLen); cy{ ado2
n = nLen; U9/6F8D1Y1
} q:a-tdv2
catch(IOException e) d(!g9H
{ P7D__hoE
e.printStackTrace (); c80!Ub@
} 2b89th
EZ+L'
5N /NUs
return n; )z Hib;O
} K Ml>~r
Y)*:'&~2e
X Z4q{^o
} T@P[jtH<d
3-6Lbe9H
dHO8 bYBH
/* .sBwJZ
**SiteInfoBean.java W^8MsdM
*/ ^=.QQo||B
package NetFox; 8%Eemk>G{
Ax{C ^u
7%)KB4(\_
public class SiteInfoBean { [#mRlL0yk
(JI[y"2
J]4pPDm
private String sSiteURL; //Site's URL <%ba 3<sg
private String sFilePath; //Saved File's Path _|f_%S8a_=
private String sFileName; //Saved File's Name -)E nr6
private int nSplitter; //Count of Splited Downloading File <!G%P4)
[L`w nP
ic=tVs
public SiteInfoBean() J*nWCL
{//nSplitter的缺省值为5 1ww#]p`1
//default value of nSplitter is 5 mi'3ibCG
this("","","",5); SDHJX8Hq
} u?%FD~l:uU
/+JHnedK
AU3>v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) , aJC7'(
{ 9kby-A4
sSiteURL= sURL; 1a@b-V2 d&
sFilePath = sPath; V*j1[d
sFileName = sName; R^k)^!/$f
this.nSplitter = nSpiltter; P,W(9&KM
Z(wj5;[G
HF;$Wf+=J
} MfG8=H2#|
PW QRy
155vY
public String getSSiteURL() F!qt=)V@w
{ o8c5~fG1
return sSiteURL; eo&^~OVT
} q.s'z}
L&LAh&%{2
_2~+%{/m,
public void setSSiteURL(String value) 5lrjM^E|
{ H63?Erh>a
sSiteURL = value; F1GFn|OA
} 5Ei4$T
r(OH
.8]buM5_G
public String getSFilePath() Y{D?&x%yq
{ (U([T-H
return sFilePath; VxW>XxG0
} 6R#.AD\
^`+Kjhht
e#!,/pE
public void setSFilePath(String value) vf0 fa46
{ k, >*.Yoh
sFilePath = value; k<A|+![
} <pIel
pv"QgH
9+"ISXS
public String getSFileName() g+%Pg@[
{ $Y?[[>u
return sFileName; XDyFe'1I
} }DFZ9,gQ
&1FyauH
N~vK8j@
public void setSFileName(String value) @d_9NOmNT
{ 2Kz407|'
sFileName = value; fRK=y+gl@
} (Qd@Q,@(s
yi:1cLq2
v9MliD'
public int getNSplitter() F@<^
{ S N;1F
return nSplitter; >A>_UT_"
} Rja>N)MzBf
L*zfZ&
@r]1;KG
public void setNSplitter(int nCount) g`I$U%a_2
{ p+}eP|N
nSplitter = nCount; d;v<rw
} PMZ*ECIJU
} nVoP:FHH
cF}9ldc
g?{7DI`
/* 3\j3vcuy
**Utility.java I>:.fHvUC
*/ >K*TgG6!X
package NetFox; N4w&g-
MZS/o3
5@EX,$h
public class Utility { ;aImz*1%t
9 =D13s(C
qkD9xFp
public Utility() cdTG ]n
{ `o6T)49
# 66vkf*
AME<V-5
} 3yu,qb'"&
[='<K
//线程睡眠 Nrzg>WQa
public static void sleep(int nSecond) HiEQs|""'
{ hD,@>ky
try{ .83z =
Thread.sleep(nSecond); [t"#4[
} gPF5|% 3)
catch(Exception e) oD_#oX5\
{ 4_w{~
e.printStackTrace (); 2YpJ4.
} =z9FjK
} Z(hRwIOF
.`+N+B(4
//日志 fX}dQN~z
public static void log(String sMsg) 8g6G},Y0
{ O>>%lr|
System.err.println(sMsg); 2qPQ3-'
} >qci$
Z'_EX7r
(z^987G
public static void log(int sMsg) H~~>ut6`
{ y])z,#%ED
System.err.println(sMsg); Bu#\W
} o&kgRv[
} { u1\M
7r$'2">K(
CxJH)H$
/* Uc5BNk7<=
**TestMethod.java k[/`G5
*/ ~%u;lr
package NetFox; LAv!s/O$=
5db9C}0
}+BbwBm&
public class TestMethod { sU;aA0kz
7=pJ)4;ZA
)U:W 9%
public TestMethod() xkmqf7w
{ ///xx/weblogic60b2_win.exe Uf<IXx&;
try{ w[s}#Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0uS6F8x@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IW- BY =C
SiteFileFetch fileFetch = new SiteFileFetch(bean); Lb%:u5X\D@
fileFetch.start(); XV:icY
} H+Se
catch(Exception e){e.printStackTrace ();} "yc@_+"\+
[:bYd}J
KmaMS(A(3
} HbQ+:B]
DT>Giic
LLW xzu!<
public static void main(String[] args) y<*/\]t9L[
{ KcF#c_f
new TestMethod(); UeN+}`!l
} bs\7 juHt
} av4g/7=
点击下载更多相关资料