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)); ]Z=al`-
} v7#|%
for(int i=0;i<nEndPos.length-1;i++) G7-k ,P^
{ ,BGUIu6
nEndPos = nStartPos[i+1]; PVljb=8F
} tW-[.Y -M,
nEndPos[nEndPos.length-1] = nFileLength; w"QZ7EyJ
} 4qsxlN>4O
} 0u( 0*Xl
*0V'rH)
{t|#>UCK
//启动子线程 <|82)hO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K@Q%NK,
for(int i=0;i<nStartPos.length;i++) iG~&uEAJ
{ OqF8KJnO;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nr}Ols
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YvP62c \
nStartPos,nEndPos,i); 9~a5R]x2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P-8QXDdr
fileSplitterFetch.start(); LH`2Y,E
} nf&5oE^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $o$WFV+h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /<k5"C%z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %Kp^wf#o9
nEndPos = " + nFileLength); :kwDa a
// fileSplitterFetch[nPos.length-1].start(); .J+F HG'
)z4eRs F|
Lh.-*H
//等待子线程结束 z> DQ
//int count = 0; C6@*l~j
//是否结束while循环 !su773vo
boolean breakWhile = false; ?q2Yk/P
s&$e}yxVO
OTJMS_IT
while(!bStop) ),j6tq[
{ hy$VG%b;#
write_nPos(); R>;&4Sjr
Utility.sleep(500); &_hEM~{
breakWhile = true; B8.}9
lq,]E/<&
O2="'w'kR
for(int i=0;i<nStartPos.length;i++) nvNF~)mu
{ QF*cdc<
if(!fileSplitterFetch.bDownOver) $}z/BV1I
{ Z*h}E
breakWhile = false; 5tLb o
break; ssoE,6kS
} .j**>&7L
} 72*j6#zS
if(breakWhile) eL}X().
break; u!F\`Gfm_
k"/Rjd(;
e-\/1N84
//count++; ]fU&?z#
//if(count>4) ib!TXWq
// siteStop(); }4h0{H
} 19!;0fe=
{Ja(+NQ
,IE.8h)H
System.err.println("文件下载结束！"); &}pF6eIar
} C+5X8
catch(Exception e){e.printStackTrace ();} O/d]2<V
} ?d{O'&|:
iDhC_F|
LXhR"PWZM\
//获得文件长度 ;Bzx}7A
public long getFileSize() #:/27
{ |>m'szca4
int nFileLength = -1; X7`-dSVE
try{ 1\Pjz Lj
URL url = new URL(siteInfoBean.getSSiteURL()); r3-<~k-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v&WK9F\
httpConnection.setRequestProperty("User-Agent","NetFox"); V|}9bNF
9&`";dg
nKnrh]hX
int responseCode=httpConnection.getResponseCode(); p4UEhT
if(responseCode>=400) 1,Mm+_)B
{ Di4GaKa/
processErrorCode(responseCode); h{$k%YJ?
return -2; //-2 represent access is error p|mFF0SL
} DG0I-"s
8e,F{>N
SBs!52
String sHeader; /`DKX }
y@1QVt04
d!Gy#<H
for(int i=1;;i++) +'MO$&6
{ k`|E&+og
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZX1/6|_
//Utility.log(in.readLine()); \b8#xT}
sHeader=httpConnection.getHeaderFieldKey(i); gTOx|bx
if(sHeader!=null) U=69q]
{ o9]32l
if(sHeader.equals("Content-Length")) _od /)#
{ Nq8 3 6HL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b7~Jl+m
break; 6-TYOUm
} eB1NM<V
} d,(q3
else 7iwck.*
break; 5p S$rf
} T#E$sZ
} Y;huTZ
catch(IOException e){e.printStackTrace ();} oq!\100
catch(Exception e){e.printStackTrace ();} <#nU 06 fN
<jF&+[*iT
.!Z5A9^
Utility.log(nFileLength); ?YZgH>7"
ex1!7A!}g
3Wbd=^hRvq
return nFileLength; U:n~S
} Y9<[n)>+
W)/f5[L
Sk!' 2y*@&
//保存下载信息（文件指针位置） !-470J
private void write_nPos() )V[j~uOU)]
{ 'h'pM#D
try{ LTo!DUi`
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xn%7{%;h
output.writeInt(nStartPos.length); QK0]9
for(int i=0;i<nStartPos.length;i++) fx(8 o+
{ zNrn|(Y%Y
// output.writeLong(nPos); 50-7L,
output.writeLong(fileSplitterFetch.nStartPos); 8~-TN1H
output.writeLong(fileSplitterFetch.nEndPos); JWg.0d$hM
} e.DN,rhqI
output.close(); H+Bon=$cE!
} [qRww]g;P|
catch(IOException e){e.printStackTrace ();} -p)`ob-
catch(Exception e){e.printStackTrace ();} p.g>+7
} ]J!#"m-]
\9#f:8Q
<5pNFj}0;X
//读取保存的下载信息（文件指针位置） ~zac.:a8
private void read_nPos() ^$O(oE(D
{ jFe8s@7
try{ R--s u:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /N*<Fq7w~
int nCount = input.readInt(); !w%c=V]tV
nStartPos = new long[nCount]; ^K1mh9O
nEndPos = new long[nCount]; t!/~_}eDJ
for(int i=0;i<nStartPos.length;i++) cRr3!<EZ
{ K3 BWj33
nStartPos = input.readLong(); [j@i^B &
nEndPos = input.readLong(); ,~Xe#eM
} z,m3U(
input.close(); i>h3UIx\
} #'%ii,;wQ
catch(IOException e){e.printStackTrace ();} (VN'1a (
catch(Exception e){e.printStackTrace ();} FO_}9<s
} ;ZI8vFb
vW*Mf}=
G5t7KI
private void processErrorCode(int nErrorCode) t6KKfb
{ L{>rN`{
System.err.println("Error Code : " + nErrorCode); B\rY\
} MDIPoS3BRa
@Nh}^D >j
CUpRtE8@[_
//停止文件下载 0.R3(O
public void siteStop() &XCd2
{ Jf7H;ZM<
bStop = true; HiK+}?I
for(int i=0;i<nStartPos.length;i++) 2oahQ: }B
fileSplitterFetch.splitterStop(); wn_ >Vi1
fuA] y4A
9x4z m
} ivl %%nY'
} Wq}6RdY$ZA
//负责部分文件的抓取 -wC}JVVcK
**FileSplitterFetch.java w]T_%mdk
*/ _)Txg2?=
package NetFox; GOA dhh-
<eSg%6z
:EHk]Hkz
import java.io.*; l{8O'4;
import java.net.*; ]=-=D9ZS3
@(6i 1Iwu9
a6z0p%sIZ
public class FileSplitterFetch extends Thread { {e2ZW]
xu-bn
RE4#a2
String sURL; //File URL RF2I_4
long nStartPos; //File Snippet Start Position 7oIHp_Zq
long nEndPos; //File Snippet End Position "u~` ZV(
int nThreadID; //Thread's ID H*<E5^#dw
boolean bDownOver = false; //Downing is over ke W7pN?
boolean bStop = false; //Stop identical r>bgCQ#-n
FileAccessI fileAccessI = null; //File Access interface #| gh
_8 K|2$X
}eZ\~2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Jg'#IM
{ !WlL RkwO
this.sURL = sURL; PuZzl%i P3
this.nStartPos = nStart; b+whZtNk7
this.nEndPos = nEnd; Z7y%
nThreadID = id; ip'{@1L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Kg<~Uf=1
} R7z @y o
N6_1iIM
)eZuG S
public void run() -t<1A8%
{ (Lz|o!>
while(nStartPos < nEndPos && !bStop) R'B_YKHBY
{ Ex_dqko
X~o;jJC
z)*{bz]
try{ lAA6tlc#C
URL url = new URL(sURL); ='kCY}dkO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o(54 A['
httpConnection.setRequestProperty("User-Agent","NetFox"); n>Oze7hVY
String sProperty = "bytes="+nStartPos+"-"; *HV_$^)=
httpConnection.setRequestProperty("RANGE",sProperty); TK'y-5W
Utility.log(sProperty); IpzU=+h
m$_l{|4z
*tpS6{4=#7
InputStream input = httpConnection.getInputStream(); jc:=Pe!E
//logResponseHead(httpConnection); 4<1V
1l^[%0
t6-fG/Kc
byte[] b = new byte[1024]; xgNV0;g,
int nRead; U5cbO{\3I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jb/C\2U4)
{ }8"i~>>a
nStartPos += fileAccessI.write(b,0,nRead); 17l?li
//if(nThreadID == 1) # 7dvT=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;IPk+,hpmi
} ]QHZ[C
CcV@YST?
@m`H~]AU
Utility.log("Thread " + nThreadID + " is over!"); V{>;Z vj1R
bDownOver = true; wS7Vo{#@\
//nPos = fileAccessI.write (b,0,nRead); -3d`e2^&}
} :si&A;k
catch(Exception e){e.printStackTrace ();} ^oq|^O
} L?8OWLjRy
} k{X+Y6'ku
vYLspZ;S
w0sy@OF
//打印回应的头信息 C.uv0
public void logResponseHead(HttpURLConnection con) _M;{}!Gc&A
{ ca0vN^Ji
for(int i=1;;i++) ^a3 (QKS
{ W95q1f#7
String header=con.getHeaderFieldKey(i); zU0JwZi
if(header!=null) 4C:dkaDq]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4V]xVma
Utility.log(header+" : "+con.getHeaderField(header)); Xooh00
else # E8?2]
break; +W-b3R:1>
} jL3 *m
} '_K`1&#U
zh?B-"O=5
-g9CW[
public void splitterStop() qOyS8tA.H
{ w*@9:+
bStop = true; I~"l9Jc!"
} ?6N\AM'
7uv"#mq
/K+;HAUTn
} l% %cU"
dKchQsgCg
vu*{+YpH
/* 7n;a_Z0s$
**FileAccess.java wc}x [cS
*//文件访问(定位，写) }+[!h=Bx
package NetFox; ?"}U?m=
import java.io.*; 0,__{?!
slr>6o%W`
FO]f 4@
public class FileAccessI implements Serializable{ .OW5R*
%.uN|o&n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mj19;nc0I
RandomAccessFile oSavedFile; #:MoZw`rlw
long nPos; !HXsxNe
iztF
|VM=:}s&
public FileAccessI() throws IOException `q\v~FT
{ % 1<@p%y/
this("",0); McdK!V
} NY[48H
F?y C=
r|3u]rt
public FileAccessI(String sName,long nPos) throws IOException VWCC(YRU|$
{ ;gRPTk$X3
oSavedFile = new RandomAccessFile(sName,"rw"); >u .u#de
this.nPos = nPos; >Bm>/%2
oSavedFile.seek(nPos); $'a]lR
} lL'K1%{+ \
^ilgd
2v*X^2+
public synchronized int write(byte[] b,int nStart,int nLen) 1o
{ AMK3I`=8WO
int n = -1; 2|M,#2E-
try{ to\$'2F"q
oSavedFile.write(b,nStart,nLen); QX(t@VP
n = nLen; k.Z?BNP
} !) d
catch(IOException e) ]HG>Og
{ r9-)+R J
e.printStackTrace (); `E>o:tff
} 9<Th: t|w
Y$3liDeL=
" M&zW&
return n; {N-*eV9#
} :3}K$
R*vfp?x
>4T7DMy
} MF::At[4
k@9q5lu;T
xtXK3[s
/* U4e9[=q`'
**SiteInfoBean.java z-S8s2.Fd
*/ `3UvKqe
package NetFox; ]RW*3X
O=Vj*G,
23zR0z(L
public class SiteInfoBean { DEzL]1;P
fvDcE]_%H
BUsAEwM
private String sSiteURL; //Site's URL J\I`#
private String sFilePath; //Saved File's Path 8O*O5
private String sFileName; //Saved File's Name 6lxZo_
private int nSplitter; //Count of Splited Downloading File dSzq}w4xY
k0DX|O8mXV
OadGwa\:s
public SiteInfoBean() QVR-`d/
{//nSplitter的缺省值为5 9Bu=8P?
//default value of nSplitter is 5 hN1{?PQ
this("","","",5); j0e1CSE
} K5d>{c
xkz`is77Y@
q +c~Bd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Fw"x4w
{ dC">AW
sSiteURL= sURL; IBv9xP]BZ
sFilePath = sPath; ?vP}#N!=d
sFileName = sName; e(-Vp7vXG
this.nSplitter = nSpiltter; 4f,%@s)zn
}e,*'mCC*
9kU|?JE
} js=w!q0)9
*>Zq79TG
XZPq4(,9}
public String getSSiteURL() (K>4^E8
{ d!q)FRzi
return sSiteURL; 7(5 wP(
} _d3/="=
Ml,87fo
2`h
public void setSSiteURL(String value) X57\sggK
{ "1$hfs
sSiteURL = value; p\,PY
} QEq>zuz5;
Y3f2RdGl
Q<Th*t
public String getSFilePath() Hh<}~s
{ G]fx3=
return sFilePath; e%&/K7I"?
} qznd'^[
?$X1X`@
6imQjtI
public void setSFilePath(String value) *ps")?tlC
{ 6rzXM`cs
sFilePath = value; \Ot,&Z k2
} p< jM%fbZk
ais"xm<V
[,p[%Dza
public String getSFileName() {= l9{K`~
{ 09rbu\h
return sFileName; yi3Cd@t({{
} t[^68]
@{UtS2L
9.$k^|~
public void setSFileName(String value) XhJbBVS|
{ /*{s1Zcb
sFileName = value; |<1
} WJ$!W
v`pIovn
H!dg(d^
public int getNSplitter() HrQft1~N
{ $[8GFv
return nSplitter; WMd5Y`y
} >`c-Fqk
Q>emyij
ibskce{H
public void setNSplitter(int nCount) 8;]U:tv
{ p_2-(n@
nSplitter = nCount; |\/Y<_)JD
} ~!a~ -:#
} F2RU7o'f.
|cCrLa2*-
r@Tq-o
/* 0SLS;s.GX
**Utility.java P mgTTI
*/ sKI{AHJ?X
package NetFox; 3]1uDgfr
W-+~r
\>*B
public class Utility { ril4*$e7^\
&]Q\@;]Aq
StJ&YYdD
public Utility() YYUWBnf30G
{ V8.o}BWY
;y"quJ'O
A296f(
} VdV18-ea
>|22%YVX
//线程睡眠 48 `k"Uy
public static void sleep(int nSecond) 6{p]cr
{ c31k%/.
try{ m#a0HH
Thread.sleep(nSecond); z tLP {q#
} @NS=
catch(Exception e) kG>d^K
{ ^ LTKX`p
e.printStackTrace (); \-B8`ah
} Lx:O Dd
} 4 u!)QG
c~a:i=y67
//日志 !yQ#E2/A
public static void log(String sMsg) A\7qPfpG
{ MjW g
System.err.println(sMsg); 8QN#PaY
} =)GhrWeVi4
m:,S1V_jl
H#luG_)
public static void log(int sMsg) +84JvOkWi
{ Hki
System.err.println(sMsg); & A%*sD6
} -~-BQ!!(
} ah\yw
tz&oe
S0 AaJty
/* uIkB&
**TestMethod.java L`Lro:E?kL
*/ *uq;O*s
package NetFox; 5P'<X p
|Y6+Y{|\
? LA>5
public class TestMethod { 2/K38t'-
W9ZfD~(3-
oyS43/."
public TestMethod() ySLa4DQf
{ ///xx/weblogic60b2_win.exe :eIu<_,}
try{ %\5d?;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {uQp$`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e==}qQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); '<.@a"DnJ
fileFetch.start(); D.hj9
} 9b8ZOk'9_
catch(Exception e){e.printStackTrace ();} #R<ErX)F
478gl o
-c"nx$
} E{m\LUd^ :
I$7#Z!P6|
"[[9i
public static void main(String[] args) 8%qHy1
{ `J%iFm/5*
new TestMethod(); H]7MNY
} 1/O7KR`K
} tiI:yq0
点击下载更多相关资料