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)); !+$QN4{9
} .Bkfe{^
for(int i=0;i<nEndPos.length-1;i++) &i3SB[|
{ sHPAr}14
nEndPos = nStartPos[i+1]; GmNCw5F
} >x%HqP#_V
nEndPos[nEndPos.length-1] = nFileLength; (7<G1$:z=
} b0'}BMJ
} \y271}'
Jq)k5X>&Sj
T\Xf0|y
//启动子线程 #xx.yn(7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T\.~!Q
for(int i=0;i<nStartPos.length;i++) V?yQm4
{ MPnMLUB$\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *PlKl_nP6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y>3zpeQ!&
nStartPos,nEndPos,i); ;Egl8Vhr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6I(Y<LZ5
fileSplitterFetch.start(); KW'nW
} ,5<AV K-#Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `vzMuL;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x(sKkm`Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 00IW9B-
nEndPos = " + nFileLength); >a*dI_XE
// fileSplitterFetch[nPos.length-1].start(); M*n94L=Sg&
ylos6]zS8
VTR4uT-
//等待子线程结束 Chl^LEN:
//int count = 0; %n6<6t`$
//是否结束while循环 @VHstjos^V
boolean breakWhile = false; 0VQBm^$(
z2Wblh"_
+fM8
while(!bStop) G"3KYBN>
{ j*gZvbO;'L
write_nPos(); oR`rs[Kj
Utility.sleep(500); }9U_4k
breakWhile = true; ;uc3_J]
?#<'w(^%#
/+B6oE>8
for(int i=0;i<nStartPos.length;i++) WF~x`w&\
{ 5{+>3J
if(!fileSplitterFetch.bDownOver) )$1j"mV
{ #ZPF&u"
breakWhile = false; 78:x{1nUM[
break; UxB3/!<5g3
} 9G6ZKqum
} ^PE|BCs
if(breakWhile) (bsywM
break; yz,_\{}
Ki:t!vAO
S['%>
//count++; ]qZj@0#7n
//if(count>4) V/DMkO#a
// siteStop(); };}N1[D
} R-W.$-rF
r/':^Ex
.PT7
System.err.println("文件下载结束！"); F@ |(
} @6|0H`kv
catch(Exception e){e.printStackTrace ();} [oBRH]9cq
} Ivcy=W=Jk
hN0h'JJ[7
T ;84Sv
//获得文件长度 T>*G1-J#
public long getFileSize() <2kv/
{ U7/ =|Z
int nFileLength = -1; SR.xI:}4
try{ Nf* .r
URL url = new URL(siteInfoBean.getSSiteURL()); K5bR7f:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [giw(4m#y
httpConnection.setRequestProperty("User-Agent","NetFox"); "WmsBdO
oPBKPGD
=B+dhZ+#S$
int responseCode=httpConnection.getResponseCode(); Z= -fL
if(responseCode>=400) p|qLr9\A
{ UWqiA`,
processErrorCode(responseCode); 7)O+s/.P)
return -2; //-2 represent access is error p]~PyzG!
} Hsov0
(6H7?nv
=],c$)
String sHeader; Z s|*+[
F#Pn]
0S+$l
for(int i=1;;i++) :qR8 e J
{ dR>$vbjh1Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gyy}-^`F
//Utility.log(in.readLine()); j5n"LC+oz
sHeader=httpConnection.getHeaderFieldKey(i); )BaGY
if(sHeader!=null) J^DyhCs
{ WFFd3TN%<
if(sHeader.equals("Content-Length")) pcOKC0b.
{ pE+:tMH;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H,EZ% Gl
break; d6m&nj
} ??#EG{{
} /18fpH|
else DH$Nz
break; K'Wv$[~Dc
} Z3Ww@&bU
} cw0@Z0
catch(IOException e){e.printStackTrace ();} tqB6:p-%
catch(Exception e){e.printStackTrace ();} p}I\H ^"8+
D'D IC
4u0?[v[Hu
Utility.log(nFileLength); 6_rgRo&
j~+(#|
@kT@IQkri
return nFileLength; i-WP#\s
} vz:VegS
(VCJn<@@
GqP02P'2
//保存下载信息（文件指针位置） 9&kPcFX B
private void write_nPos() ^*y1Fn0
{ pfl^GgP#
try{ XfIsf9
output = new DataOutputStream(new FileOutputStream(tmpFile)); #{k+^7aQ
output.writeInt(nStartPos.length); ?mVSc/
for(int i=0;i<nStartPos.length;i++) u]9 #d^%V
{ NYxL7:9
// output.writeLong(nPos); Jfv'M<I
output.writeLong(fileSplitterFetch.nStartPos); qM Qu!%o
output.writeLong(fileSplitterFetch.nEndPos); "~Kph0-
} >wYmx4W>
output.close(); UT 7'-
} V=>]&95-f
catch(IOException e){e.printStackTrace ();} ?%Q=l;W.
catch(Exception e){e.printStackTrace ();} s nNd7v.U6
} l8%BRG
0,#n_"
a>Aq/=
//读取保存的下载信息（文件指针位置） BP&]t1p
private void read_nPos() \7o7~pll
{ >G[:Q s
try{ %\'G2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X$%W&:
int nCount = input.readInt(); L&|^y8
nStartPos = new long[nCount]; `6NcE-oJ
nEndPos = new long[nCount]; @L607[!?
for(int i=0;i<nStartPos.length;i++) Sq2 8=1%
{ j39"iAn
nStartPos = input.readLong(); u?z,Vs"
nEndPos = input.readLong(); w&hCtc
} [%Z{Mp'g
input.close(); ?aB%h |VA
} VGCd)&s
catch(IOException e){e.printStackTrace ();} &[PA?#I`
catch(Exception e){e.printStackTrace ();} E3CwA8)k
} ;kG"m7-/
< jX5}@`z
*xx)j:Sc2
private void processErrorCode(int nErrorCode) r0\C2g_X
{ {8;}y[R
System.err.println("Error Code : " + nErrorCode); B1Z;
} [ 'B u
]h`d>#Hw!
1p-<F3;
//停止文件下载 a=B $L6*4
public void siteStop() %82:?fq
{ OwDwa~
bStop = true; xj]^<oi<
for(int i=0;i<nStartPos.length;i++) Efpju(
fileSplitterFetch.splitterStop(); anKflt3
?ZhBS3L
\mt Y_O
} `Xi)';p
} bXM&VW?OP
//负责部分文件的抓取 \ZSqZDq
**FileSplitterFetch.java :"i2`y;u
*/ i8*(J-M
package NetFox; (2RuQgO
B\ZCJaMb
?;_Mxal'
import java.io.*; +QSH*(,
import java.net.*; :pvVm>
cI@'Pr4:FJ
f$?`50D"1
public class FileSplitterFetch extends Thread { e?GzvM'2
^>fr+3a"P
3@0!]z^W
String sURL; //File URL eQfXUpk3@I
long nStartPos; //File Snippet Start Position T&<ee|t@{
long nEndPos; //File Snippet End Position y"_rDj`
int nThreadID; //Thread's ID a]8W32
boolean bDownOver = false; //Downing is over w`/~y
boolean bStop = false; //Stop identical 6jov8GIAt
FileAccessI fileAccessI = null; //File Access interface J0t_wMJa
*~UK5Brf1
4jVd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3]&le[.
{ `0W+(9}
this.sURL = sURL; 6>'>BamX
this.nStartPos = nStart; UnZc9 6
this.nEndPos = nEnd; W yP]]I.
nThreadID = id; (r1"!~d@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SEM-t
} zP$"6~.
vXak5iq>X
{s2eOL5I|%
public void run() zRR^v&.9K
{ ki?V eFp
while(nStartPos < nEndPos && !bStop) !|J2o8g
{ 1l.HQ IS
-(#`JT8
4Le{|B
try{ qzu(4*Gk6
URL url = new URL(sURL); 3)(uC+?[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7G Jhc
httpConnection.setRequestProperty("User-Agent","NetFox"); )[E7\pc
String sProperty = "bytes="+nStartPos+"-"; ftV~!r
httpConnection.setRequestProperty("RANGE",sProperty); @,]$FBT"5
Utility.log(sProperty); !Okl3 !fC
+}f}!h;
9SU/86|N
InputStream input = httpConnection.getInputStream(); MJn=
//logResponseHead(httpConnection); *4Z! 5iOs
)<5hga][~a
0/~{,
byte[] b = new byte[1024]; w)>/fG|;
int nRead; $WQm"WAKe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HoZsDs.XZ
{ x*:"G'zT
nStartPos += fileAccessI.write(b,0,nRead); 3_J({
//if(nThreadID == 1) <.lt?!.ZH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :4Y5
} &i*e&{L7
C&.Q|S2_
QC1\Sn/
Utility.log("Thread " + nThreadID + " is over!"); 2FN#63
bDownOver = true; {C%f~j
//nPos = fileAccessI.write (b,0,nRead); TO/SiOd
} mU>lm7'
catch(Exception e){e.printStackTrace ();} ]C-a[
} -_>E8PhM
} tYhNr
fDChq[LAn
T>5N$i
//打印回应的头信息 Et&PzDvU
public void logResponseHead(HttpURLConnection con) Ol8Yf.e_
{ pO N@
for(int i=1;;i++) Z..s /K{
{ 7K24sHw;%
String header=con.getHeaderFieldKey(i); c <X( S
if(header!=null) [3v&j_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OXV9D:bIa
Utility.log(header+" : "+con.getHeaderField(header)); G~f|Sx
else 22EI`}"J
break; b C"rQJg
} k!g%vx
} ca'c5*Fs
C]krJse@
6'.CW4L
public void splitterStop() e8)8QmB{o
{ u X(#+
bStop = true; kM76?M
} @CA{uP;
$KsB'BZy
ca:Vdrw`
} zy8D&7Ytf
EV R>R
|#22pq?RP
/* wqJ1^>TB
**FileAccess.java '.XR,\g>
*//文件访问(定位，写) wHs4~"EY9
package NetFox; @-O%u*%J
import java.io.*; r3~YGY
,d8*7my
4`:Eiik&p
public class FileAccessI implements Serializable{ #D%l;Ae
is{H >#+"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YF)c.Q0
RandomAccessFile oSavedFile; oox;8d4}y
long nPos; ezhK[/E=
}t1J`+x%
({hW
public FileAccessI() throws IOException Ka8Bed3
{ 9gETWz(3I
this("",0); A3Vj3em
} ^{64b
c,5yH
L ?S#3@Pa
public FileAccessI(String sName,long nPos) throws IOException -'j|U[&N\
{ *,Sa*-7(
oSavedFile = new RandomAccessFile(sName,"rw"); 8q|T`ac+N
this.nPos = nPos; )fbYP@9>a
oSavedFile.seek(nPos); ?b?YiK&yz
} AN+S6t
o_.`&Q6n
vk3C&!M<a
public synchronized int write(byte[] b,int nStart,int nLen) Bv^5L>JZ/
{ .QDeS|l
int n = -1; P5Pb2|\*
try{ R7Z!
oSavedFile.write(b,nStart,nLen); piAFxS<6
n = nLen; v.>95|8
} [9~6, ;6
catch(IOException e) nOU.=N v`
{ *YP;HL
e.printStackTrace (); Q&&oP:4~X*
} {BD G;e
x,QXOh\a
sE\Cv2Gx
return n; Tuy5h5
} t0)XdIl8
6FEIQ#`{
xDn#=%~+x
} LbnW(wr6:(
Gg{M
N[sJ5oF
/* Rrp-SR?O
**SiteInfoBean.java A7zL\U4
*/ nZ#0L`@"Y
package NetFox; _O`s;oc
JQA]O/|N
P u,JR
public class SiteInfoBean { +?GsIp@>jh
rpv<'$6
byX)4&
private String sSiteURL; //Site's URL \mNN ) K@
private String sFilePath; //Saved File's Path &>vfm9
private String sFileName; //Saved File's Name Z \;{e'#o
private int nSplitter; //Count of Splited Downloading File 1raq;^e9
@gjA8mL
e^orqw/I
public SiteInfoBean() oN=>U"<\1
{//nSplitter的缺省值为5 0W]vK$\F*
//default value of nSplitter is 5 /(DnMHn\
this("","","",5); 6Vu)
} rWip[>^
B[;aNyd<
}k_'a^;C1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !5>PZ{J
{ %G'P!xQhy
sSiteURL= sURL; ?l^NKbw
sFilePath = sPath; ;~(yv|f6
sFileName = sName; ]eo%eaA
this.nSplitter = nSpiltter; >4nQ&b.u
B;J8^esypD
J(Zz^$8]<?
} }KR"0G[f
|_%q@EID
T<o8lL
public String getSSiteURL() %ZGG6Xgw
{ I"HA( +G
return sSiteURL; jXYjs8Iy
} F_nXsKem
y*#+:D]o*
mIv}%hD
public void setSSiteURL(String value) wfQImCZ>l
{ y`8jz,&.
sSiteURL = value; mtVoA8(6
} h<bCm`qj
j-7aJj%
8_T9[]7V8
public String getSFilePath() \n^;r|J7k
{ > QG@P
return sFilePath; pLtK:Z
} O-qpB;|
P5&8^YV`N
{ukQBu#}<
public void setSFilePath(String value) !twYjOryH[
{ N;i\.oY
sFilePath = value; |P7FPmn
} =JN{j2xY
UZJ#/x5F
+3]V>Mv
public String getSFileName() ln_[@K[oX
{ a.fdCI]%
return sFileName; '8;'V%[+
} Pdk#"H-j
k;jXVa
Qn)AS1pL+
public void setSFileName(String value) &A~hM[-
{ hY|-l%2f
sFileName = value; e;9x%kNs!
} Mt&n|']`8
@nIoIz D~
8+8L'Yv;
public int getNSplitter() !EGpI@
{ E_Fm5zb?X
return nSplitter; K7wU tg
} h8icF}m
ZNJ<@K-
- #-Bo
public void setNSplitter(int nCount) 6dhzx; A
{ k\\e`=
nSplitter = nCount; ]E#W[6'VtB
} hpYW1kfQl
} "b\@.7".
u4ZOHy_O^
2W}jbOy
/* W6V((84(O
**Utility.java mnFmShu
*/ +HlZ?1g
package NetFox; 9hjzOJPuga
nxe9^h7m
9s?gI4XN
public class Utility { I?_WV_T&
x;A.Ll
"%#CMCE|f
public Utility() 5E =!L g
{ &.P G2f*
RM>A9nv$\
vK$wc~
} aev(CY,z
]U,m 1
//线程睡眠 @?bY,
public static void sleep(int nSecond) \s7/`
{ /4KHf3Nr
try{ &FWz7O>1
Thread.sleep(nSecond); DC0ON`
} ?*'0;K13
catch(Exception e) K?>sP%m)
{ 9(lcQuE9
e.printStackTrace (); RV%)~S@!R
} <7`U1DR=
} 4<Kxo\\S
M9?f`9
//日志 F:8@ ]tA&
public static void log(String sMsg) Q+s2S>U{v
{ AOef1^S=
System.err.println(sMsg); ~vcua@
} ahFK^ #s
<MoyL1=
ijKQ`}JA
public static void log(int sMsg) dtig_s,)D
{ LQV&;O4'
System.err.println(sMsg); M"6J"s
} O)D$UG\<
} Xh}G=1}
,h<xY>
pUa\YO1J
/* FcyFE~>2
**TestMethod.java "^wIixOH5
*/ ;7*T6~tv
package NetFox; HhwAzk/G~
X$_pDF&\z
S3&n?\CO:
public class TestMethod { FsS.9 `B
U65oh8x
V!NRBXg
public TestMethod() wLNkXC
{ ///xx/weblogic60b2_win.exe ]~!CJ8d
try{ 5F#FC89Kk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T[MDjhv'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tToP7q^
SiteFileFetch fileFetch = new SiteFileFetch(bean); \UZ7_\
fileFetch.start(); @mb'!r
} RDEK=^J
catch(Exception e){e.printStackTrace ();} c)=a;_h
4vV\vXT*
KY?ujeF
} fNBI!=
{7%(m|(
G++<r7;x
public static void main(String[] args) t#w,G
{ g!OcWy)7
new TestMethod(); `26.+>Z7
} M*D@zb0ia
} [I/ZzDMX
点击下载更多相关资料