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)); *C81DQ
} 9 )1 8
for(int i=0;i<nEndPos.length-1;i++) =IQ+9Fl2
{ q6h'=By
nEndPos = nStartPos[i+1]; "@1e0`n Q
} P|> fO'
nEndPos[nEndPos.length-1] = nFileLength; B{UL(6\B
} sb Wn1 T U
} v71j1Q}6
4K_rL{s0U
AJ_''%$I3:
//启动子线程 F?UI8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Arg604V3
for(int i=0;i<nStartPos.length;i++) ~)\9f 1O{^
{ zn| S3c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gnjh=anVX1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b&AGVWhh
nStartPos,nEndPos,i); `mar-r_m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J#h2~Hz!
fileSplitterFetch.start(); = GN1l[X
} 3/rEXKS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xbbQ)sH&m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y0!-].5UH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d5zv8?|X+
nEndPos = " + nFileLength); 4e6x1`Y{xB
// fileSplitterFetch[nPos.length-1].start(); C-i9F%..
KxyD{W1
oy8L{8?
//等待子线程结束 X$aN:!1
//int count = 0; F't4Q
//是否结束while循环 Wpgp YcPS
boolean breakWhile = false; HeV6=&#
K(&I8vAp
KIY/nu
while(!bStop) tPv3nh
{ en6Kdqe
write_nPos(); 5Lmhip
Utility.sleep(500); }V20~ hi
breakWhile = true; qH#?, sK ^
;DQ{6(
> -P UY
for(int i=0;i<nStartPos.length;i++) asDk@Gcu
{ ;WydXQ}Q^
if(!fileSplitterFetch.bDownOver) eIZ7uSl
{ ^HJvT)e4
breakWhile = false; p:*)rE
break; }e/#dMEi
} v5 |XyN"
} N_3$B=
if(breakWhile) mGss9eZa
break; Ri[ v(Zf
'o D31\@I
Mnj\t3:
//count++; ]i$<<u
//if(count>4) $ z4JUr!m
// siteStop(); #%Z 0!
} ( (.b&
O!uZykdX4!
x;Qs_"t];3
System.err.println("文件下载结束！"); I},]Y~Y3
} S&yKi
catch(Exception e){e.printStackTrace ();} Pu|PIdu!08
} g8=j{]~C
+JyD W%a:L
OoW,mmthj>
//获得文件长度 47S1mxur
public long getFileSize() |hx"yy'ux
{ NOC8h\s}(
int nFileLength = -1; {RG4m{#9
try{ CcGE4BB
URL url = new URL(siteInfoBean.getSSiteURL()); sBN"eHg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HPGIz!o
httpConnection.setRequestProperty("User-Agent","NetFox"); V/p+Xv(Zt
c(@(j8@S
E#?Bn5-uBs
int responseCode=httpConnection.getResponseCode(); xqZZ(jZ
if(responseCode>=400) &c?q#-^)\+
{ [-ONs
processErrorCode(responseCode); Q7 4Q|r7
return -2; //-2 represent access is error /Bt+Ov3k
} pr;n~E 'kq
r6JQRSakR
m`;dFL7"E
String sHeader; rI'kGqU
^bD)Tg5K
=nVEdRU
for(int i=1;;i++) N7Kg52|
{ /$EX-!ie
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L<7KmN4VX
//Utility.log(in.readLine()); -0I]Sm;$
sHeader=httpConnection.getHeaderFieldKey(i); Rcn6puZt
if(sHeader!=null) g6AEMer
{ JWh5gOXd
if(sHeader.equals("Content-Length")) +#;t.&\80N
{ Z=[qaJ{]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VnjhEEM!
break; k},@2#W]
} QPD[uJ(I
} `6No6.\J
else _nUvDdEs,
break; [Sj _=
} `@_jDo
} %qycxEVP
catch(IOException e){e.printStackTrace ();} K~chOX
catch(Exception e){e.printStackTrace ();} a^#\"c
z9}WP$W
O:%,.??<%
Utility.log(nFileLength); q0m>NA
MvCB|N"qy
xYLTz8g=
return nFileLength; zfsGf'U
} BN_I#8r
nB|m!fi<
GLBzlZ?
//保存下载信息（文件指针位置） {uCXF~v
private void write_nPos() 6"o,)e/z
{ T)Uhp
try{ ,(;TV_@$
output = new DataOutputStream(new FileOutputStream(tmpFile)); r(ZMZ^
output.writeInt(nStartPos.length); cv=H6j]h|
for(int i=0;i<nStartPos.length;i++) ?hFG+`"W
{ +A;AX.mr
// output.writeLong(nPos); 6_=t~9sY
output.writeLong(fileSplitterFetch.nStartPos); B4#XQ-
output.writeLong(fileSplitterFetch.nEndPos); P&snIJ
} ov 'g'1}
output.close(); >h Rq
} GG=R!+p2
catch(IOException e){e.printStackTrace ();} X/8TRiTFv
catch(Exception e){e.printStackTrace ();} Fkvf[!Ci
} =Hd+KvA
>)j`Q1Qc\
rOo|.4w
//读取保存的下载信息（文件指针位置） s7Z+--I)L
private void read_nPos() _{C =d3
{ {W' 9k
try{ d71|(`&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `Eg~;E:
int nCount = input.readInt(); } %bP9
nStartPos = new long[nCount]; _SQQS67fu"
nEndPos = new long[nCount]; mS9ITe M
for(int i=0;i<nStartPos.length;i++) Z,"f2UJ
{ i)1013b
nStartPos = input.readLong(); -V F*h.'
nEndPos = input.readLong(); gebDNl\Y2
} EyDH-}Y
input.close(); k .#I ;7
} j /)A<j$
catch(IOException e){e.printStackTrace ();} olxnQYFo
catch(Exception e){e.printStackTrace ();} FoW|BGA~
} 4(D1/8
U)JwoO
])9|j
private void processErrorCode(int nErrorCode) Q/%]%d
{ 0s72BcP
System.err.println("Error Code : " + nErrorCode); WNK)IC~c
} @c-| Sl
0F-%C>&g
}Y&|v q
//停止文件下载 PNB E
public void siteStop() gWGh:.*T
{ -}CMNh
bStop = true; K[^BRn
for(int i=0;i<nStartPos.length;i++) 8#ZF<BY
fileSplitterFetch.splitterStop(); `gX$N1(
V6!1(|
PLueH/gC.
} 'E)g )@^
} i`7(5L~`
//负责部分文件的抓取 ?m\? #
**FileSplitterFetch.java 08qM?{zo^
*/ -%ftPfm
package NetFox; F T$x#>
9YvK<i&I
<i ";5+
import java.io.*; pmuT7*<19
import java.net.*; DmiZ"A
=`OnFdI
Ca}V5O
public class FileSplitterFetch extends Thread { l_i&8*=Px
^US ol/
>*h3u7t
String sURL; //File URL '&!:5R59
long nStartPos; //File Snippet Start Position c2Yrg@) [
long nEndPos; //File Snippet End Position $)Ty@@7C
int nThreadID; //Thread's ID -+z8bZ
boolean bDownOver = false; //Downing is over miB+'n"zS
boolean bStop = false; //Stop identical uhvn1"
FileAccessI fileAccessI = null; //File Access interface o#QS: '|
@ruWnwb
y41~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h1+y.4
{ NRMEZ\*L
this.sURL = sURL; +GL[uxe"
this.nStartPos = nStart; Ya29t98Pk
this.nEndPos = nEnd; Jy P$'v~
nThreadID = id; 0gsRBy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nz%Yi?AF
} oR~s \Gt
$6~t|[7:%Y
P{2j31u`
public void run() i'3)5
{ b6d}<b9#
while(nStartPos < nEndPos && !bStop) 7qLB9r
{ I#:Dk?"O2
S#b)RpY
Y-.aSc53
try{ XaH;
URL url = new URL(sURL); 4O7 {a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YM&i
httpConnection.setRequestProperty("User-Agent","NetFox"); [{.9#cQ"
String sProperty = "bytes="+nStartPos+"-"; f>[{1M]n\
httpConnection.setRequestProperty("RANGE",sProperty); qkA8q@Y4|
Utility.log(sProperty); ddwokXx (
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|e91KmiqJ
InputStream input = httpConnection.getInputStream(); Ge ?Q)N
//logResponseHead(httpConnection); |F49<7XB[~
fS]Z`U"
l9naqb:iP
byte[] b = new byte[1024]; M:t"is
int nRead; er.;qV'Wz6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q#lFt,.y
{ Huc|HL#C
nStartPos += fileAccessI.write(b,0,nRead); MogIQ
//if(nThreadID == 1) KtcuGI/A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3oM&#a
} b!T-{Ns6
&*; Z(ul&9
S{nBQB<
Utility.log("Thread " + nThreadID + " is over!"); Qov*xRO6
bDownOver = true; 4k)0OQeW6
//nPos = fileAccessI.write (b,0,nRead); l{Xy %8
} g(l:>=g]?
catch(Exception e){e.printStackTrace ();} TU^s!Tj
} P\%aJ'f~
} gR${S|Z#u4
vT#m 8Kg
GI%9Tif
//打印回应的头信息 7X8n|NZRH7
public void logResponseHead(HttpURLConnection con) M;sT+Z{
{ J@qwz[d i
for(int i=1;;i++) Xb.# =R
{ (!%w
String header=con.getHeaderFieldKey(i); LY2QKjgP
if(header!=null) lz4M)pL^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #ds@!u+&
Utility.log(header+" : "+con.getHeaderField(header)); 7 b8pWM
else >M7(<V
break; SN;_.46k
} %=)%$n3=-M
} kudXwj
87rHW@\](
|XJ|vQGU
public void splitterStop() 2XrYm"6w
{ zKQXmyO
bStop = true; c@lH
} *0z'!m12
Ebp=du
DpIk$X
} a6'T]DW0W
vk<4P;A(G
cHon' tS
/* $s,(-C
**FileAccess.java m}]\^$d
*//文件访问(定位，写) ~b})=7n.
package NetFox; ztC>*SX
import java.io.*; \R,8xID_t
[_HOD^
cG!dMab(
public class FileAccessI implements Serializable{ c3N,P<#
?&bB?mg\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Wb;D9Z
RandomAccessFile oSavedFile; ASa)xf9
long nPos; vAzSpiv-
Z`>m
@DK`#,
public FileAccessI() throws IOException `%$+rbo~
{ lI;ACF^
this("",0); zd3^k<
} ~N8$abQJV
m{by%
YXDuhrs}
public FileAccessI(String sName,long nPos) throws IOException ycrM8Mu 3
{ l8+;)2p!
oSavedFile = new RandomAccessFile(sName,"rw"); ft?c&h;At
this.nPos = nPos; V"8w:?
oSavedFile.seek(nPos); #,;Q|)AD:e
} iu QMVtv
ORhvo,.u
d?A!0;(*
public synchronized int write(byte[] b,int nStart,int nLen) :_pn|
{ MLN+ BuS
int n = -1; vA*Q}]Ov
try{ >njX=r.
oSavedFile.write(b,nStart,nLen); y>]Yq-
n = nLen; BO'7c1FU
} < mp_[-c
catch(IOException e) v8>bR|n5
{ AL*M`m_
e.printStackTrace (); u_6x{",5I
} Sw`+4 4
;Mz7emt
\`-a'u=S
return n; :~'R|l
} ITfz/d8
?cB26Zrcb
rVB\\
} N;* wd<
->2m/d4a
[p_<`gU?
/* 2 @t?@,c
**SiteInfoBean.java $J*lD-h-
*/ ilwIqj
package NetFox; unt{RVR%
P9qZjBS
=a(]@8$!1
public class SiteInfoBean { PBgU/zVn
w/@ tH
*V{Y.`\
private String sSiteURL; //Site's URL gq050Bl)
private String sFilePath; //Saved File's Path "8/BVW^bv
private String sFileName; //Saved File's Name uuYeXI;
private int nSplitter; //Count of Splited Downloading File "6>+IF
#dkSAS
m=V69 a#
public SiteInfoBean() d bHxc@H
{//nSplitter的缺省值为5 L4v26*P
//default value of nSplitter is 5 |};-.}u^`h
this("","","",5); a'?V:3 ]
} !H~PF*,hY
bOD]`*q
hZ-?-F?*@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7myYs7N8[
{ H Yw7*
sSiteURL= sURL; Z*YS7 ~
sFilePath = sPath; n,`j~.l-=>
sFileName = sName; 3Hf_!C=g
this.nSplitter = nSpiltter; HEF\TH9
!%/(a)B$^$
mLDuizWI
} +f'@
ebhV;Q.
]BfJ~+ N
public String getSSiteURL() b 4A1M
{ =jvL2ps<
return sSiteURL; `Af5%m[
} a!\^O).pA
(;(2n;i[M
WMnxN34
public void setSSiteURL(String value) )3)x/WM
{ 3 V$ \s8
sSiteURL = value; ,e;_ Vb
} afd.v$63
synueg
lA n^)EL
public String getSFilePath() 7towjwr
{ vCn\_Nu;W&
return sFilePath; U+:Mu]97
} [E9)Da_)i
JN3&(t
Gp2Cwyv
public void setSFilePath(String value) NGmXF_kqN
{ o':K4r;
sFilePath = value; s,-}}6WO
} B]:?4Ov
7E;`1lh7
vGchKN~_
public String getSFileName() lf_q6y
{ p_CCKU
return sFileName; (Ji=fh+
} SyIi*dH
Nh1, w
*kt%.wPJ
public void setSFileName(String value) %!]CP1S
{ n,Q^M$mS0
sFileName = value; O}X@QG2_
} VN]j*$5
o_cAelI[!
xmHW,#%ui\
public int getNSplitter() ,soXX_Y>
{ OZ}o||/Rc
return nSplitter; p+16*f9,^
} BQ(sjJ$v6F
}ni@]k#q<
HjZf3VwI
public void setNSplitter(int nCount) j<}y(~
{ 8?h&FbmB
nSplitter = nCount; I36ClOG
} #=#bv`
} 60r0O5=|Fl
UD_8#DO{m1
G4wJv^6i9
/* Wx8n)
**Utility.java ]Ryg}DOQ
*/ }UqL2KXi4
package NetFox; 2C#b-Y1~N
Su*Pd;
CQ'4 ".7
public class Utility { wc?YzXP+
0xUn#&A~
##'uekSJ
public Utility() J/\^3rCB
{ ,AG k4]
!jRs5{n^Ol
[>|6qY$D
} Zz!yv(e)H
XF?"G<2
//线程睡眠 Y.E]U!i*
public static void sleep(int nSecond) 4q\gFFV4
{ 7A{,)Y/w ^
try{ Y/qs\c+
Thread.sleep(nSecond); nBzju?X)I
} l|fb;Giq=D
catch(Exception e) _7,4C?
{ ,{BF`5bn|
e.printStackTrace (); CW?R7A/
} -"}nm!j /5
} 2cko GafG{
x{1S!A^
//日志 tW%!|T5/
public static void log(String sMsg) M)CQ|P
{ (*Q8!"D^6
System.err.println(sMsg); +4V"&S|&
} r(I&`kF<
y(Tb=:
QQQN}!xPj
public static void log(int sMsg) v[<;z(7Qk
{ `9nk{!X\
System.err.println(sMsg); <UbLds{+Uo
} h3MZLPe
} ij02J`w:Ra
7:n OAN}%
#Wely~
/* ||'A9
**TestMethod.java GyGF<%nq
*/ OVEQ^\Q5D
package NetFox; vd0uI#g%#
6gB;m$:fV
U^&y*gX1
public class TestMethod { '(SqHP|8&g
\{a 64
)uy2,`z
public TestMethod() y@Ak_]{b
{ ///xx/weblogic60b2_win.exe 0t -=*7w%
try{ #* Iyvx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )J1xO^tE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0>U7]wZKc
SiteFileFetch fileFetch = new SiteFileFetch(bean); ShJBOaE; -
fileFetch.start(); J@o$V- KK
} A<[BR*n
catch(Exception e){e.printStackTrace ();} ]".SW5b_
7?qRz
sYd)r%%AU
} d1u6*&@lf
c<5(c%a
r^;1Sm
public static void main(String[] args) ~D_Wqr
{ |[MtUWEW
new TestMethod(); A8j$c~
} {3K`yDF
} /N=M9i\;
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