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)); /*(&Dmt>
} jN!VrRA
for(int i=0;i<nEndPos.length-1;i++) jdkqJ4&i
{ %6la@i
nEndPos = nStartPos[i+1]; u s8.nL/
} nG%<n
nEndPos[nEndPos.length-1] = nFileLength; )4RSo&9p`
} p2 !w86 F
} 0j2mTF(C
[QIQpBL
7- |N&u
//启动子线程 LRR)T: e}q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kP1cwmZ7F
for(int i=0;i<nStartPos.length;i++) a4mRu|x
{ |-TxX:O-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |S]T,`7u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j_.tg7X
nStartPos,nEndPos,i); R5xV_;wD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oA8A @,-L
fileSplitterFetch.start(); h!`KX2~
} yQ!keGj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p)?6~\F:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Js(MzL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )"](?V
nEndPos = " + nFileLength); Mp(;PbVD
// fileSplitterFetch[nPos.length-1].start(); ';m;K (g
iO"ZtkeNr
1.5R`vKn]
//等待子线程结束 :jJ0 +Q
//int count = 0; ,u9>c*Ss\
//是否结束while循环 Z`#XB2,
boolean breakWhile = false; <B'PB"R3y
+UiJWO
8\G"I
while(!bStop) 2J (nJT"
{ 8Y_lQfJa
write_nPos(); ts;^,|h
Utility.sleep(500); ]TN/n%\
breakWhile = true; /4}y2JVv)
[#fz[U
k\RS L
for(int i=0;i<nStartPos.length;i++) -XnOj2
{ 4?]s%2U6
if(!fileSplitterFetch.bDownOver) -wVuM.n(Z
{ FH{p1_kZ=
breakWhile = false; {{AZW
break; sq@c?!'
} q3`~uTzk
} PAH#yM2Ic
if(breakWhile) j=c< Lo`
break; a*t>Ks'C
LYiIJAZ.
D~M*]&
//count++; |E;+j\
//if(count>4) 0U !&|i\
// siteStop(); +|H,N7a<
} GiKhdy
""m/?TZq'
~%h&ELSw
System.err.println("文件下载结束！"); J ~KygQ3%
} !%B-y9\
catch(Exception e){e.printStackTrace ();} oi8M6l
} ge1U1o
ce*?crOV
Kw2]J)TO
//获得文件长度 `6BQ6)7
public long getFileSize() p.H`lbVY
{ IJC]Al,df
int nFileLength = -1; ]=59_bkD:s
try{ 5H,(\Xd
URL url = new URL(siteInfoBean.getSSiteURL()); i^8w0H<-@v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /B|"<`-H
httpConnection.setRequestProperty("User-Agent","NetFox"); Qwp2h"t`
m*\LO%s]E
xe9\5Gb}
int responseCode=httpConnection.getResponseCode(); PR*EyM[T
if(responseCode>=400) 9< S
{ u$X =2u:P
processErrorCode(responseCode); ;,7m
return -2; //-2 represent access is error u68ic1
} c~}FYO$
k=G c#SD5_
nU0##
String sHeader; @H^\PH?pp
7K+eI!m.s
m>?|*a,
for(int i=1;;i++) Kjpsz];
{ lTVz'ys
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g4{0
//Utility.log(in.readLine()); F~~9/#
sHeader=httpConnection.getHeaderFieldKey(i); T!Lv%i*|Y
if(sHeader!=null) %Aa_Bumf*:
{ 4q(,uk&R[
if(sHeader.equals("Content-Length")) @Y<fj^]k
{ }:[MSUm5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1#8~@CQ ::
break; {Z1-B60P
} %d<UMbS^
} +n)bWB%
else *}_i[6_\E
break; jo<Gf 5
} 6/vMK<Fz9
} !& >LLZ
catch(IOException e){e.printStackTrace ();} [E"3?p
catch(Exception e){e.printStackTrace ();} nFe
Yv2L0bUo:
>h~>7i(A
Utility.log(nFileLength); {hm-0Q
3>=G-AH/$K
SpOSUpl%
return nFileLength; OAEa+V
} Mc,p]{<<AV
b,'rz04^
db}lN
//保存下载信息（文件指针位置） &vIj(e9Y
private void write_nPos() LX #.
{ 9*Fc+/
try{ aC<fzUD;
output = new DataOutputStream(new FileOutputStream(tmpFile)); jpOcug`f
output.writeInt(nStartPos.length); $$*0bRfd4=
for(int i=0;i<nStartPos.length;i++) |!1iLWQ
{ ldc`Y/:{
// output.writeLong(nPos); (a~V<v"
output.writeLong(fileSplitterFetch.nStartPos); Yp8XZ3
output.writeLong(fileSplitterFetch.nEndPos); V8b^{}nxt
} 1^[]#N-Bu
output.close(); =/\l=*
} ;=@?( n
catch(IOException e){e.printStackTrace ();} ?%/*F<UVQ
catch(Exception e){e.printStackTrace ();} zy~*~;6tW
} v+dT7*^@
ha9 dz
ZmI#-[/
//读取保存的下载信息（文件指针位置） QkLcs6)R
private void read_nPos() NH1ak(zHW
{ $-6[9d-N
try{ IVeA[qA0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); = N:5#A
int nCount = input.readInt(); .TNJuuO
nStartPos = new long[nCount]; 6)FM83zk)K
nEndPos = new long[nCount]; pBn;:
for(int i=0;i<nStartPos.length;i++) r4iT 9D
{ &yqk96z
nStartPos = input.readLong(); e`)zR'As
nEndPos = input.readLong(); f9'dZ}B
} q ^Gj IP
input.close(); Hl8\*#;C&>
} kq(]7jU$[
catch(IOException e){e.printStackTrace ();} h*sL' fJ]
catch(Exception e){e.printStackTrace ();} $cLZ,N24
} 6^FUuj.
d ;,C[&
=H^~"16
private void processErrorCode(int nErrorCode) (: mF+%(
{ t1G2A`
System.err.println("Error Code : " + nErrorCode); #rp)Gc
} 1J&hm[3[K
~c\2'
nQn=zbZ3
//停止文件下载 9A}y^=!`
public void siteStop() 7'@~TM
{ wB<cW>6
bStop = true; {P%\& \{F
for(int i=0;i<nStartPos.length;i++) t~Ic{%bdA
fileSplitterFetch.splitterStop(); ZKi?;ta=
I#W J";kqB
VY0-18 o
} -or)NE
} T'N/A9{q
//负责部分文件的抓取 gpCWXz')i
**FileSplitterFetch.java ,ZnL38GW
*/ lnV!Xuf
package NetFox; >-(,BfZ
2F ~SH
,rhNXx
import java.io.*; :r&4/sN}<
import java.net.*; V<d`.9*}
X"T)X#:)
qf%p#+:B3
public class FileSplitterFetch extends Thread { xI~c~KC
"b`3
p,\(j
String sURL; //File URL ;|oem\dKv
long nStartPos; //File Snippet Start Position <_4'So>
long nEndPos; //File Snippet End Position _n4C~
int nThreadID; //Thread's ID f6#1sO4"
boolean bDownOver = false; //Downing is over S^~ lQ|D
boolean bStop = false; //Stop identical 4>]B8ZxH
FileAccessI fileAccessI = null; //File Access interface @rr\Jf""z
hr g'Z5n
BqOMg$<\[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException al4X}
{ kB-<17
this.sURL = sURL; gyCXv0*z
this.nStartPos = nStart; `,FhCT5
this.nEndPos = nEnd; A.<M*[{q
nThreadID = id; >a: 6umY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z~;@Mo"*f
} Ul|htB<1:
K!gocNOf
t5S!j2E
public void run() @EH@_EwYV
{ 85+w\KuEY
while(nStartPos < nEndPos && !bStop) ,6wGdaMR
{ U#4>GO;A
a!;K+wL >
DWU(ld:_
try{ yuF\YOA9
URL url = new URL(sURL); Kq:vTz&<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d*:J0J(
httpConnection.setRequestProperty("User-Agent","NetFox"); PB@jh}
String sProperty = "bytes="+nStartPos+"-"; M+L0 X$}NZ
httpConnection.setRequestProperty("RANGE",sProperty); "GAKi}y">v
Utility.log(sProperty); &GI'-i
RP6hw|
gq+#=!(2
InputStream input = httpConnection.getInputStream(); 1xU)nXXb
//logResponseHead(httpConnection); H`T}k+e2-N
JiiYl&#
qn` \g
byte[] b = new byte[1024]; $XrX(l5
int nRead; Y,X0x-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e:6mz\J
{ lq)[
nStartPos += fileAccessI.write(b,0,nRead); cUU"*bA#
//if(nThreadID == 1) {JW_ZJx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9NqZ&S
} 4aG}ex-s|
sQT<I]e
RIF*9=,S
Utility.log("Thread " + nThreadID + " is over!"); L>,xG.oG
bDownOver = true; :tLMh08h
//nPos = fileAccessI.write (b,0,nRead); }9L;|ul6
} jft@ 'W53
catch(Exception e){e.printStackTrace ();} Q7?[@2HN
} -M`+hVs?
} }M9I]\
(vbI4&r
Dfd%Z;Yu
//打印回应的头信息 4I;$a;R!
public void logResponseHead(HttpURLConnection con) u:\DqdlU`
{ {uiL91j.
for(int i=1;;i++) v79\(BX
{ V"|j Dnn5
String header=con.getHeaderFieldKey(i); xc$jG?83#
if(header!=null) wmit>69S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m?`$NJST
Utility.log(header+" : "+con.getHeaderField(header)); r7*'s
else _Ns_$_
break; P".rm0@R
} IPlkv{^
} Rhh.fV3
=OooTZb:x-
'k9 1;T[
public void splitterStop() o>\epQt~/p
{ rd}|^&e!Dy
bStop = true; ,}$[;$ye
} lmB+S
U p: M[S
3F9AnS
} -2y>X`1Y
B%KfB VC
4NmLbM&C8
/* ;d||u
**FileAccess.java ~01Fp;L/
*//文件访问(定位，写) mvGj !'
package NetFox; 7gT^ZL
import java.io.*; &fgfCZz'
Tw9?U,]
n7'X.=o7
public class FileAccessI implements Serializable{ UQ+!P<>w
zT jk^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o$,e#q)8
RandomAccessFile oSavedFile; GhY MO6Q4
long nPos; rFYw6&;vOi
R"[U<^
[!b=A:@
public FileAccessI() throws IOException s;YuB#Z
{ gJuA*^
this("",0); 7cZ(gdQ/
} 9K_p4 mq
Xh"8uJD
|ea}+N
public FileAccessI(String sName,long nPos) throws IOException Cb;49;q
{ P:v|JER
oSavedFile = new RandomAccessFile(sName,"rw"); zgA/B{DaC;
this.nPos = nPos; bJ9K!6s??`
oSavedFile.seek(nPos); 33b 3v\N
} BW&)Zz
_.3O(?p,
5KwT(R o
public synchronized int write(byte[] b,int nStart,int nLen) ]jwF[D
{ UU]a).rz
int n = -1; +[$ Q C*
try{ nL&[R}@W
oSavedFile.write(b,nStart,nLen); wm_o(Z}
n = nLen; dzyp:\&9
} @(LEuYq}
catch(IOException e) Fs;_z9ej-u
{ 0^&-j.9
e.printStackTrace (); MbjMO"}
} ^`oyf{w@
.wz.Jr`{
S(h+,+289
return n; \>r<z46x
} %v 1NDhaXz
8yn}|Y9Fu
^jZ4tH3K
} SpiI9)gp
3+2cD
e2$k %c~
/* o-%DL*^5
**SiteInfoBean.java FTC,{$
*/ G,JNUok
package NetFox; x9VR>ux&
fr([g?F%D
eU.HS78
public class SiteInfoBean { C.oC@P
u.L{3gkT
zQ~8(E]Rf
private String sSiteURL; //Site's URL uPveAK}h
private String sFilePath; //Saved File's Path q3-V_~5^/z
private String sFileName; //Saved File's Name OMVK\_oXo
private int nSplitter; //Count of Splited Downloading File UFY_.N~
7Q3a0`Iq
k874tD
public SiteInfoBean() x6={)tj
{//nSplitter的缺省值为5 [agp06 $D?
//default value of nSplitter is 5 Q7@.WG5
this("","","",5); o$+"{3svw?
} x*2'I
x7l3&;yDv
yUzpl[*e^o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1lLL9l{UVw
{ 0413K_
sSiteURL= sURL; f|X./J4Bl
sFilePath = sPath; ?oO<PR}y
sFileName = sName; LU4k/
this.nSplitter = nSpiltter; }hd:avze
`8rInfV
s j{i
} rYYAZ(\8
j[<}l&
U$5 lh
public String getSSiteURL() WGeTL`}dh
{ bI?YNt,
return sSiteURL; 3>t^Xu~
} <"Cacfg
yC]X&1,:z
b 5X~^L
public void setSSiteURL(String value) :RE.md
{ Ysz&/ry
sSiteURL = value; NWq>Z!x`
} l3C%`[MB
"=97:H{!
OPsg3pW!]
public String getSFilePath() =Vm"2g,aA
{ T2^0Q9E?
return sFilePath; ) ]x/3J@
} N1O.U"L;
``p()^zT
-$js5Gx1
public void setSFilePath(String value) rG*Zp7{
{ Y}pCBw
sFilePath = value; Q(\U'|%J
} 8NRc+@f|m
<p74U( V
z]Dbca1a`
public String getSFileName() }+fMYgw
{ R|Lr@k{6+r
return sFileName; [j]3='2}G
} v8>?,N#
~\^h;A'3
r-];@
public void setSFileName(String value) VaIFE~>E&
{ &>m# "A\^
sFileName = value; <s7OY`(8
} wtY*{m2
D+ )R_
"+6:vhP5
public int getNSplitter() W+C@(}pt
{ "V;5Lp b
return nSplitter; feH|sz`e
} }Ra'`;D$
1k *gbXb
Uz`K#Bz
public void setNSplitter(int nCount) NBUSr}8|
{ _*I@ J/
nSplitter = nCount; Uczb"k5
} @1w9!\7Vt
} jeM/8~^4-
[8o!X)
t)*MLg<C
/* R\B-cU[,
**Utility.java nf7l}^/UE
*/ .%(Q*ioDh
package NetFox; cCoa3U/
]H4T80wm&
0~5'O[NhF
public class Utility { ?x|8"*N
EN =oA P
0=2D90
public Utility() El}."}l&
{ =D2jJk?AX
.9< i
$~[k?D
} 0?tn.<'B8T
H|1owmbD
//线程睡眠 I}#_Jt3R
public static void sleep(int nSecond) 5gPcsn"D
{ fJb<<6C
try{ Nl3@i`;
Thread.sleep(nSecond); LvsNU0x
} =X0"!y"
catch(Exception e) YMidSfi
{ %YI Xk1
e.printStackTrace (); =2 3H/
} 43"`gF]
} V?a+u7*U&
X_}2xo|T
//日志 |,&5.|E 7
public static void log(String sMsg) \m3;<A/3n
{ L@"1d.k_
System.err.println(sMsg); 0<8pG:BQ
} +$hqwNh@Z@
y7;i4::A\
bF#*cH
public static void log(int sMsg) nty^De%
{ meHnT9a^
System.err.println(sMsg); XF`,mV4
} 7g}lg8M
} '8Q:}{
1kG{z;9
jb!R
/* 6[dLj9 G%
**TestMethod.java Q]Ymv:M,
*/ 0wxlsny?
package NetFox; k}5Sz
]"jJgO^
r+}5;fQJ
public class TestMethod { n(|~z
8| 6:
4xg7oo0iJ
public TestMethod() /.'tfy$
{ ///xx/weblogic60b2_win.exe s<i& q {r
try{ BM(8+Wj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]}3AP!:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zHI_U\"8D
SiteFileFetch fileFetch = new SiteFileFetch(bean); t8Sblgq
fileFetch.start(); {Lex((
} om`x"x&6
catch(Exception e){e.printStackTrace ();} Ag3[Nu1
JMMT886
U4J9bp|
} |mSFa8G@
/kl41gx
gD"]uj<
public static void main(String[] args) R. sRH/6
{ {9tKq--@E9
new TestMethod(); 2;Ij~~
} F__j]}?
} 7q>Y)*V
点击下载更多相关资料