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)); .6#2i <oPW
} M4\Io]}-M
for(int i=0;i<nEndPos.length-1;i++) Zotv]P2k
{ wuQkeWxJ
nEndPos = nStartPos[i+1]; YWFHiB7x
} f+AIxSw
nEndPos[nEndPos.length-1] = nFileLength; ox#4|<qM
} z# B) b5
} 1bs95Fh9Q
d^^>3L!h
Lr&BZM
//启动子线程 -;z\BW5y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dUSuhT
for(int i=0;i<nStartPos.length;i++) T/5UlW|\
{ U6PUt'Kk@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '|R|7nQAj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S3cQC`^
nStartPos,nEndPos,i); ~zRd||qv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I =pdjD
fileSplitterFetch.start(); -H]O&u3'c
} N6'Y N10
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uGWk(qn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =&GV\ju
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W#\4"'=I
nEndPos = " + nFileLength); UU`qI}Ys8F
// fileSplitterFetch[nPos.length-1].start(); ]F!h~>
w2GY,,R
| 'G$}]H
//等待子线程结束 v}@6"\
//int count = 0; GssoT<Y)Z
//是否结束while循环 Mla,"~4D5
boolean breakWhile = false; cG6+'=]3<
\v Go5`
^k=[P
while(!bStop) SfT]C~#$N
{ 0IuU4h5Fr
write_nPos(); OYy8u{@U:
Utility.sleep(500); 9,+LNZ'k
breakWhile = true; +.St"f/1
7lu;lAAP
gO36tc:ce
for(int i=0;i<nStartPos.length;i++) \g/E4U.+
{ :;QLoZh^
if(!fileSplitterFetch.bDownOver) S)?B I
{ '#?hm-Ga
breakWhile = false; '/?&Gol-
break; u"ow?[E
} 4esf&-gG
} HtlXbzN%)
if(breakWhile) lom4z\6
break; akoILX~u
%l,EA#89s
d"a`?+(Q
//count++; "`zw(
//if(count>4) 9UX-)!
// siteStop(); j^M@0o
} 5/<Y,eZ/
;H.r6
$[e*0!e
System.err.println("文件下载结束！"); M Cz3RZK
} k9 E?5
catch(Exception e){e.printStackTrace ();} O"GzeEY7
} 8~7EWl
'yqp
Lm/^ 8V+
//获得文件长度 ~ nIZg5
public long getFileSize() +dRTHz
{ TkykI
int nFileLength = -1; +8"H%#~
try{ h#>67gJV
URL url = new URL(siteInfoBean.getSSiteURL()); Im=E?t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); klKt^h-
httpConnection.setRequestProperty("User-Agent","NetFox"); qSR %#
HU'}c*d]
O;r8l+
int responseCode=httpConnection.getResponseCode(); 5k@k
if(responseCode>=400) F7df
{ 3[$VW+YV
processErrorCode(responseCode); EP @=i
return -2; //-2 represent access is error hLF@'ln
} F6Ixu_s
.u)YZN0\
R?k1)n
String sHeader; &o(? }W
l6RJour
G[<iVt$y
for(int i=1;;i++) TG($l2
{ %pdfGM9g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aOOY_S E
//Utility.log(in.readLine()); aG!!z>
sHeader=httpConnection.getHeaderFieldKey(i); uG<+IT|x
if(sHeader!=null) g.'4uqU
{ \AG,dMS
if(sHeader.equals("Content-Length")) ' x|B'
{ : f Wh7X3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f3O3pIA
break; U i;o/Z3
} 4V=dD<3m
} `S2=LJ
else ]yyfE7{q
break; !&X}?NK
} _\"?:~rUN
} ,}[,]-nVx
catch(IOException e){e.printStackTrace ();} ^I^k4iw4
catch(Exception e){e.printStackTrace ();} 8Og9P1jVh
vwg\qKqSM
}9'rTLM
Utility.log(nFileLength); Jyn>:Yq(
J{91 t |
2>mDT
return nFileLength; = hpX2/]
} v/)dsSNZ0u
){/y-ixH
r$+9grm<
//保存下载信息（文件指针位置） b'G4KNW
private void write_nPos() h0!j;fn
{ 5s0H4?S
try{ GXwV>)!x
output = new DataOutputStream(new FileOutputStream(tmpFile)); "C>KKs }
output.writeInt(nStartPos.length); =|6IyL_N
for(int i=0;i<nStartPos.length;i++) jjs-[g'}
{ "<kmiK/
// output.writeLong(nPos); xv /w %
output.writeLong(fileSplitterFetch.nStartPos); om(#P5cSM;
output.writeLong(fileSplitterFetch.nEndPos); 1m&(3%#{
} 4&?%"2
output.close(); ?qdG)jo=
} H|Eu,eq-E
catch(IOException e){e.printStackTrace ();} ,5nrovv
catch(Exception e){e.printStackTrace ();} \aG>(Mr
} ";Lpf]<
he/FtkU
:R_(+EK1
//读取保存的下载信息（文件指针位置） pNDL:vMWP
private void read_nPos() 3ZC[H'|
{ 7;Wj^#
try{ Hkpn/,D5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6$IAm#
int nCount = input.readInt(); q4VOK 'N
nStartPos = new long[nCount]; QjPcfR\
nEndPos = new long[nCount]; ' e-FJ')|
for(int i=0;i<nStartPos.length;i++) G.9?ApG9
{ @]~\H-8
nStartPos = input.readLong(); jA6:-Gz
nEndPos = input.readLong(); a7ZPV1k
} w+Ag!O}.L
input.close(); pbu8Ib8z
} |n0 )s% 8`
catch(IOException e){e.printStackTrace ();} !Y5O3^I=u
catch(Exception e){e.printStackTrace ();} (CEJg|,
} I'C{=?
=3sBWDB[
cU+/I>V
private void processErrorCode(int nErrorCode) 7Rq;V=2YV
{ ($]y*|Obn
System.err.println("Error Code : " + nErrorCode); 9NVe>\s_
} bd9]'
A|jaWZM-
/mvuSNk
//停止文件下载 ^oj)#(3C
public void siteStop() %3Y&D]
{ 6kHAoERp
bStop = true; d!8`}L:=M
for(int i=0;i<nStartPos.length;i++) U<*ZY`B3
fileSplitterFetch.splitterStop(); ;/$zBr`'
Cdc6<8
n pBpYtG
} dqnxhN+&
} nx=Zl:Q}
//负责部分文件的抓取 u=A&n6Q[Vo
**FileSplitterFetch.java |nB2X;K5~
*/ nKch_Jb
package NetFox; :v=Yo
|eJ4"OPC
lQldW|S>
import java.io.*; $TWt[
import java.net.*; :FB#,AOa_
?~;G)5
G!@tW`HO
public class FileSplitterFetch extends Thread { R9~%ORI#;
nxCwg>
rk{DrbRx
String sURL; //File URL 2?#IwT'
long nStartPos; //File Snippet Start Position na_Y<R`
long nEndPos; //File Snippet End Position &ciU`//`
int nThreadID; //Thread's ID ]k5l]JB
boolean bDownOver = false; //Downing is over $#1i@dI
boolean bStop = false; //Stop identical //Ck1cI#h
FileAccessI fileAccessI = null; //File Access interface 0[jy
q B5cF_
K)N7Y=C3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pX+`qxF\
{ \5cAOBja
this.sURL = sURL; EJ"[{AV
this.nStartPos = nStart; # KK>D?.:
this.nEndPos = nEnd; 8" XbW7^o
nThreadID = id; _m#M^<0n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Yu`b[]W
} ng^`s}?o
Z[s{
G ,An8GR%&
public void run() ~bhesWk8!
{ XTyJ*`>
while(nStartPos < nEndPos && !bStop) kK>PFk(
{ CQ9B;i`
ojni+}>_
9;NR
try{ *^ g7kCe(
URL url = new URL(sURL); vE^Hk!^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L]I)E`s
httpConnection.setRequestProperty("User-Agent","NetFox"); 5v<BB`XWp
String sProperty = "bytes="+nStartPos+"-"; C AVqjT7
httpConnection.setRequestProperty("RANGE",sProperty); ^W{+?q'
Utility.log(sProperty); iZyhj%#
LcI,Dy|P
76(-!Z@=J
InputStream input = httpConnection.getInputStream(); ayTEQS
//logResponseHead(httpConnection); R&PQU/t)
4Bsx[~ u&
HeCQF=R
byte[] b = new byte[1024]; B0T[[%~3M
int nRead; !7]4sXL{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 80U07tJ
{ ]W-l1
nStartPos += fileAccessI.write(b,0,nRead); P33x/#VVE
//if(nThreadID == 1) nJ<h}*[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p(fYpD
} S;[9 hI+
dq?{?~3
OB FG!.)
Utility.log("Thread " + nThreadID + " is over!"); x|&A^hQ
bDownOver = true; ]#z^[XG
//nPos = fileAccessI.write (b,0,nRead); epqX2`!V
} ,IX:u1mO
catch(Exception e){e.printStackTrace ();} Ii_X^)IL(
} fH-V!QYGF
} >vF=}1_L
A M8bem~
B[w~bW|K
//打印回应的头信息 p)NhV
public void logResponseHead(HttpURLConnection con) &W)Lzpx8c
{ 96x0'IsaG
for(int i=1;;i++) apPn>\O
{ c4E=qgP
String header=con.getHeaderFieldKey(i); cD{I*t$
if(header!=null) SRuNt3wW6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BR;f!
Utility.log(header+" : "+con.getHeaderField(header)); l$=Y(Xk
else f^\qDvPur
break; Q5b~5a
} /"Ws3.p
} q^ lx03
#0V$KC*>
)>abB?RZ
public void splitterStop() :yO.Te F
{ u^&2T(xGi
bStop = true; l( /yaZ`
} 1$vsw
dP}=cZ~
eAR]~ NiW
} Op%}.9ed
H*BzwbM?
8DHohhN
/* AC:cV='
**FileAccess.java !l-^JPb
*//文件访问(定位，写) ]"Z*Hq z
package NetFox; +MU|XT_5|6
import java.io.*; _PUgK\
P0WI QG+
:d\ne
public class FileAccessI implements Serializable{ 7/%{7q3G>
oju)8H1o#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X;25G
RandomAccessFile oSavedFile; 4 qMO@E_
long nPos; IMjz#|c
#Ux*":
GAG=4g
public FileAccessI() throws IOException huVw+vAA
{ .4P5tIn\
this("",0); s8 S[w
} jSNUU.lur
n%GlOKC
PEqO<a1Z8
public FileAccessI(String sName,long nPos) throws IOException ~$xLR/{y
{ WxwSb`U|
oSavedFile = new RandomAccessFile(sName,"rw"); _EMq"\ND
this.nPos = nPos; g#b[-)Qx
oSavedFile.seek(nPos); r:Uqtqxh
} /;>U0~K
ti$d.Kc(
p!5=1$
public synchronized int write(byte[] b,int nStart,int nLen) {nTQc2T?;
{ Uv|z c
int n = -1; -ZwQL="t
try{ k/[*Wz$W
oSavedFile.write(b,nStart,nLen); "#Ov!t
n = nLen; ]gI>ay"\QA
} 49. @Uzo
catch(IOException e) 1haNca_6,
{ <5rs~
e.printStackTrace (); #m yiZL%
} &s m7R i
HRP4"#9R
]r++YIg!j
return n; |KEq-
} =d07c
?z,^QjQ}
IRy!8A=X
} K6"#&0
::bK{yZm
fNjxdG{a
/* =fk+"!-i%"
**SiteInfoBean.java %@JNX}Y'
*/ +|6 '7Z(9
package NetFox; ukM11LD5x
;:(kVdb
my+y<C-o`
public class SiteInfoBean { }2dz];bR
ia=eFWt.
i$MYR @
private String sSiteURL; //Site's URL \GA6;6%Oo
private String sFilePath; //Saved File's Path s%Ez/or(T
private String sFileName; //Saved File's Name JBX#U@k>I
private int nSplitter; //Count of Splited Downloading File {|)u).n|
}py6H[
9e^HTUFbG
public SiteInfoBean() $@]tTz;b
{//nSplitter的缺省值为5 _m3}0q
//default value of nSplitter is 5 ch2Qk8
this("","","",5); H(f~B<7q
} .-Y3oWV
S<), ,(
FtBYPSGz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "{a-I=s\C
{ 7kDX_,i
sSiteURL= sURL; Ph[P$: 9
sFilePath = sPath; :0K[fBa
sFileName = sName; fa#xEWaFr
this.nSplitter = nSpiltter; b(@[Y(_R
F!v`._]
oq00)I1
} o5~o Rmsr
y k=o
[AAG:`
public String getSSiteURL() :5kgJu
{ &E98&[`7
return sSiteURL; }9Yd[`
} QP+zGXd}(
9G)Sjn`AQ
BLc&q)
public void setSSiteURL(String value) GL4-v[]6I
{ a`SQcNBf*
sSiteURL = value; S 6e<2G=O
} o80?B~o
z=ItKoM*<
MF+J3)
public String getSFilePath() ~lB im$o
{ Co e q<
return sFilePath; 9Z! j
} a%3V< "f
L`"PaIMz
G01J1Ll}
public void setSFilePath(String value) XL@Y!
{ 5HWVK.
sFilePath = value; CH |A^!Zm
} OGmOk>_
:4o08M%
i={ :6K?^
public String getSFileName() Q_p!;3
{ 7D5;lM[_
return sFileName; v0pyyUqS
} !@ERAPuk
8<cD+Jtj
*eE&ptx1
public void setSFileName(String value) :]?y,e%xu,
{ t- Rp_2t
sFileName = value; y\}39Z(]
} REd"}zDI
?QzA;8H
X^L)5n+$X
public int getNSplitter() z$'_ =9yZ
{ ZY%]F,Y
return nSplitter; ,,*i!%Adw
} >3R%GNw
XhF7%KR
j\V9o9D
public void setNSplitter(int nCount) lZpa)1.tiC
{ jY.iQBhjEB
nSplitter = nCount; 7|~j=,HU+Z
} 3:q\]]]S
} %m8;Lh-X
PFP/Pe Ng;
)ESF)aKMiz
/* 5o2W[<%v
**Utility.java TF)OBN~/
*/ &?.k-:iN
package NetFox; E_VLI'Hn?
4JlB\8rc
l.tNq$3pS
public class Utility { 6mH0|:CsY
7nh,j <~;2
] i;xeo,
public Utility() !E\xn^
{ ;d"F'd
q%HT)^F9oO
7C7eXJ9q
} {~=Edf
)"j)9RQ}
//线程睡眠 fX)C8J^=G
public static void sleep(int nSecond) cO$ PK
{ wKe$(>d"L
try{ 4H4U
Thread.sleep(nSecond); Q}G'=Q]Juz
} aL63=y
catch(Exception e) MMs#Y1dH
{ 3q*y~5&I
e.printStackTrace (); @=KuoIV
} +8+@Az[e0
} 2FHWOy /N@
8= jl]q$<
//日志 B1]5%B
public static void log(String sMsg) [<~1.L^I
{ W}6(;tI
System.err.println(sMsg); _sU|<1
} l V[d`%(
{3RY4HVT?
`N0Mm7
public static void log(int sMsg) AF5$U8jf
{ !f~ =p
System.err.println(sMsg); ]fH U/%
} "*o54z5"
} JX_hLy@`
e/@tU'$
3JuWG\r)l
/* dQfVdqg
**TestMethod.java i#I+
*/ B7"/K]dR:
package NetFox; ?`+46U%
P.bBu
cnm&oC 6
public class TestMethod { ["|' f
#*^vd{fl
p7b`Z>}
public TestMethod() R/)cEvB-0
{ ///xx/weblogic60b2_win.exe VV/6~jy0
try{ lSw9e<jYO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q'kZ3G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CJA5w[m
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2mVcT3
fileFetch.start(); x <^vJ1
} iV X12
catch(Exception e){e.printStackTrace ();} f&+=eUp
K-Bf=7F,
J(*QtF
} +QcgLq
w,L PM+
Ux_tHyc/
public static void main(String[] args) :+;AXnDM~
{ l?CUd7P(a
new TestMethod(); C`F*00M{
} fuM+{1}/E
} MS{purD
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