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)); {14fA)`%
} qJa H,
for(int i=0;i<nEndPos.length-1;i++) { VfXsI
{ r|fL&dtr
nEndPos = nStartPos[i+1]; Zd}9O jz5
} m_?~OL S
nEndPos[nEndPos.length-1] = nFileLength; D4lG[qb
} 0oZ= yh
} O1U=X:Zl
FQ7T'G![
u=?.}Pj
//启动子线程 Q4!_>YZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +yH7v5W
for(int i=0;i<nStartPos.length;i++) z2_*%S@
{ .B]MpmpK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IS{wtuA.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pnowy;
nStartPos,nEndPos,i); #@9/g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *K6g\f]b#
fileSplitterFetch.start(); FaQe_;
} b_#m}yZ6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gmO!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9`A;U|~E@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8:c-k|CX
nEndPos = " + nFileLength); ]}-7_n#cC
// fileSplitterFetch[nPos.length-1].start(); rq/yD,I,
r6MMCJ|G
;4^Rx
//等待子线程结束 kHghPn?8]
//int count = 0; 2G67NC?+
//是否结束while循环 RXpw!
boolean breakWhile = false; rb2S7k0{
Jr ,;>
D3Ig>gKo?m
while(!bStop) ug!s7fo^
{ J6s`'gFns
write_nPos(); qo90t{|c
Utility.sleep(500); Ustv{:7v
breakWhile = true; nQX:T;WL@
uD$u2
hk(ZM#Bh
for(int i=0;i<nStartPos.length;i++) +,TRfP Fb
{ 85|OGtt
if(!fileSplitterFetch.bDownOver) U0 Yll4E
{ (cAIvgI
breakWhile = false; h5{'Q$Erl
break; 1MP~dRZ$
} MSQEO4ge
} VgG0VM
if(breakWhile) qPX~@^`9
break; L O_k@3
SO|NaqWa
[fya)}
//count++; @Q ]=\N:
//if(count>4) yYIf5S`V]
// siteStop(); L3u&/Tn2
} LEbB(x;@
BOb">6C
JgKO|VO
System.err.println("文件下载结束！"); -LoZs ru
} ]_mb7X>
catch(Exception e){e.printStackTrace ();} lk^Ol&6
} c@!_/0
$Uq|w[LA
-[4T
//获得文件长度 ^e2VE_8L
public long getFileSize() Xy|So|/bKd
{ F 5bj=mI
int nFileLength = -1; n71r_S*
try{ 6@h/*WElG
URL url = new URL(siteInfoBean.getSSiteURL()); \%JgH=@ :=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M)J5;^["
httpConnection.setRequestProperty("User-Agent","NetFox"); NR5gj-B[
-j#2}[J7
v}}F,c(f
int responseCode=httpConnection.getResponseCode(); 7Utn\l
if(responseCode>=400) 'Vzp2
{ EA@.,7F
processErrorCode(responseCode); i^X]j
return -2; //-2 represent access is error xBThq?N?
} zsEc(
9|^2",V
BM%e0n7
String sHeader; APn|\
m)ky*"(
:[p}
for(int i=1;;i++) 59LZv-l
{ )al]*[lY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -]N x,{
//Utility.log(in.readLine()); 9tU]`f
sHeader=httpConnection.getHeaderFieldKey(i); ''A_[J `>
if(sHeader!=null) 2@n{yYwy
{ [`#CXq'
if(sHeader.equals("Content-Length")) O%WIf__Q
{ #`qx<y*S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dc+>m,3$
break; !fV+z%:
} Fd%#78UEo}
} #5Qpu
else c?(4t67|
break; vONasD9At
} a5dLQxb
} -P(efYk
catch(IOException e){e.printStackTrace ();} jnkR}wAA
catch(Exception e){e.printStackTrace ();} !hA-_
6+#Ydii9E
MD}w Y><C
Utility.log(nFileLength); f&NgS+<K$
=J]&c?I
,Q3T Tno ,
return nFileLength; >2y':fO
} %8RrRW
JU4<|5H
NlA,'`,
//保存下载信息（文件指针位置） oM X
private void write_nPos() 8 `v-<J
{ n2"a{Ofhlf
try{ +RHS!0
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^rB8? kt
output.writeInt(nStartPos.length); aj-Km`5r}
for(int i=0;i<nStartPos.length;i++) HDz5&7* .
{ YU'k#\gi*
// output.writeLong(nPos); aG-vtld
output.writeLong(fileSplitterFetch.nStartPos); $f$SNx)),
output.writeLong(fileSplitterFetch.nEndPos); f%A;`4`q
} nQF(vTDN
output.close(); %e8@*~h@
} ]vB$~3||
catch(IOException e){e.printStackTrace ();} pE3?"YO
catch(Exception e){e.printStackTrace ();} vSGH[nyCY
} ^)470K`%)
/`Ug9,*
WqR&&gz
//读取保存的下载信息（文件指针位置） PF0_8,@U
private void read_nPos() ^Y?k0z
{ #z'
try{ M:=J^0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :;v~%e{k
int nCount = input.readInt(); 8v6(qBK
nStartPos = new long[nCount]; (=FRmdeYl1
nEndPos = new long[nCount]; .o6Or:L
for(int i=0;i<nStartPos.length;i++) I:-Wy"i
{ P7ao5NP
nStartPos = input.readLong(); 3#n_?-
nEndPos = input.readLong(); O"+gQXe
} ,=uD^n:
input.close(); mn'A9er
} m=1N>cq '
catch(IOException e){e.printStackTrace ();} w$>u b@=
catch(Exception e){e.printStackTrace ();} 8:q1~`?5"b
} %6t:(z
#]-SJWf3
;'gWu
private void processErrorCode(int nErrorCode) JB\UKZXw
{ p0]=QH
System.err.println("Error Code : " + nErrorCode); mwO6g~@`
} ^23~ZHu
*j|~$e}C
3h]g}&k
//停止文件下载 mupT<_Y
public void siteStop() ~EW(Gs!=C
{ M.JA.I@XC
bStop = true; `T1
for(int i=0;i<nStartPos.length;i++) }czrj%6
fileSplitterFetch.splitterStop(); W PC]%:L"
.zf~.R;>
gZVc 5u<
} xnjf
} ]|#+zx|/D
//负责部分文件的抓取 "BAK !N$9
**FileSplitterFetch.java g9OY<w5s]
*/ IM*y|UHt
package NetFox; g/4[N{Xf
T%+#xl
\-E^lIVF
import java.io.*; V(}:=eK
import java.net.*; pG_;$8Hc
zxEL+P
7o\@>rNWP
public class FileSplitterFetch extends Thread { y4yhF8E>;U
^"E^zHM(
,.S~ Y
String sURL; //File URL 9p85Pv [M=
long nStartPos; //File Snippet Start Position )w em|:H
long nEndPos; //File Snippet End Position zE*li`@
int nThreadID; //Thread's ID vo?9(+:|e
boolean bDownOver = false; //Downing is over cF*TotU_m
boolean bStop = false; //Stop identical :S]%6gb8G
FileAccessI fileAccessI = null; //File Access interface c&6I[R
1> ?M>vK
n>z9K')
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xl{=Y< ;
{ >[f?vrz
this.sURL = sURL; hy1oq7F(Q
this.nStartPos = nStart; 'I|v[G$l
this.nEndPos = nEnd; j\yjc/m
nThreadID = id; H;is/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $L`d&$Vh
} 'JtBZFq
>\R+9p:o
_IMW{
public void run() YO`]UQ|dc
{ Brw@g8w-X
while(nStartPos < nEndPos && !bStop) t}a: p6D]
{ kb%;=t2
Xc++b|k
#&+{mCjs
try{ T}Tp$.gB
URL url = new URL(sURL); 2F[ q).
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S E<FL/x1#
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Ee?6]bN
String sProperty = "bytes="+nStartPos+"-"; VO5#Qgen
httpConnection.setRequestProperty("RANGE",sProperty); ^^u5*n+5
Utility.log(sProperty); s3N'02G
_{ue8kGt
[>3./YH`
InputStream input = httpConnection.getInputStream(); #!B4 u?"m
//logResponseHead(httpConnection); !"e5h`/ADM
B^=-Z8
c?Y*Y
byte[] b = new byte[1024]; UsG~row:!
int nRead; :]K4KFM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z9E\,Ly
{ 3ZuZ/=
nStartPos += fileAccessI.write(b,0,nRead); !vi>U|rh
//if(nThreadID == 1) D_2:k'4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]|pe>:gf'
} _oL?*ks
yZ7&b&2nLn
Yu/ID!`Z
Utility.log("Thread " + nThreadID + " is over!"); krxo"WgD
bDownOver = true; OG~gFZr)6
//nPos = fileAccessI.write (b,0,nRead); u2I*-K
} r+!YIk
catch(Exception e){e.printStackTrace ();} @)+AaC#-
} gk4;>}
} Z3e| UAif
8LJ8 }%*
&,vcJ{.
//打印回应的头信息 ,oe <
public void logResponseHead(HttpURLConnection con) u]wZQl#-
{ .8g)av+
for(int i=1;;i++) ~%F9%=
{ 8$cLG*=h4
String header=con.getHeaderFieldKey(i); CZe ]kXNv
if(header!=null) .~db4d]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w_c"@CjkE
Utility.log(header+" : "+con.getHeaderField(header)); X56q-|
else wo}H'Q}Hj
break; }v;V=%N+v
} ~Gp[_ %K
} yf)%%&
UXz<)RvB
Mexk~zA^
public void splitterStop() ;a!S!%.h
{ P{`C^W$J^
bStop = true; M7\szv\Zc=
} fm%t^)E
A|[?#S((]
@u+]aI!`-
} eeg)N1\
fb7;|LF
G>_*djUf
/* ]#<4vl\
**FileAccess.java ]EbM9Fo-U
*//文件访问(定位，写) Kg*Q
package NetFox; NX.6px17
import java.io.*; ?,Xw[pR
;O5zUl-`
pad*oPH,
public class FileAccessI implements Serializable{ gaxsv[W>^
P8 c`fbkX2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q_8+HEvo
RandomAccessFile oSavedFile; A 'be8
long nPos; @s&71a
Q}JOU
BVQqY$>
public FileAccessI() throws IOException m 0C@G5
{ X05/uX{
this("",0); h&iC;yj=
} P5V}#;v
6wRd<]C
K3&qq[8.e
public FileAccessI(String sName,long nPos) throws IOException c):/!Q
{ #zy:a%
oSavedFile = new RandomAccessFile(sName,"rw"); Es`Px_k
this.nPos = nPos; DK~xrU'
oSavedFile.seek(nPos); ~Cttzn]pR
} (x|T+c"bAX
G>=*yqo
octL"t8w
public synchronized int write(byte[] b,int nStart,int nLen) 2s8a $3
{ l30EKoul)
int n = -1; Wi<m{.%\E
try{ @{e}4s?7od
oSavedFile.write(b,nStart,nLen); *Q.>-J<S
n = nLen; =BeygT^
} ~/U1xk%
catch(IOException e) @bLy,Xr&
{ pF>i-i
e.printStackTrace (); I{&[[7H
} klYX7?
:4w ?#
U>SShpmZA
return n; Vt~{Gu-Y
} Pm?KI<TH~
(E3b\lST
`[yKFa I
} #z%fx
kH1~k,|\&K
Kw^7>\
/* aO[w/cGQ
**SiteInfoBean.java >6-`}G+|
*/ ?UR0:f:}oc
package NetFox; }v{LRRi
$wa{~'
E&w7GZNt
public class SiteInfoBean { I 34>X`[o
a-tmq]]E
2pCaX\t
private String sSiteURL; //Site's URL E]d.z6k
private String sFilePath; //Saved File's Path Ne!lH@ql
private String sFileName; //Saved File's Name wQf-sk#
private int nSplitter; //Count of Splited Downloading File ?z+eWL
{YC@T(
H8jpxzXv
public SiteInfoBean() 1GRCV8"Z^
{//nSplitter的缺省值为5 >R_&Ouh:
//default value of nSplitter is 5 G_JA-@i%
this("","","",5); 372rbY
} .Efk*
(WJRi:NP?
Jpq~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t?gic9 q
{ $I>w]
sSiteURL= sURL; NxY#NaE:?4
sFilePath = sPath; ^76]0`gS
sFileName = sName; re<{ >
this.nSplitter = nSpiltter; t@;p
|Ez>J+uye(
B[Scr5|
} P+sW[:
3?yg\
(CL%>5V
public String getSSiteURL() l'qg8
{ D_7,m%Z:
return sSiteURL; T-L||yE,h
} vr l-$ii
u=sp`%?
l)\! .X
public void setSSiteURL(String value) _[3D
{ +sA2WK]
sSiteURL = value; |df Pki{
} 5qm`J,~k
3hH<T.@)
=nS3p6>rZ
public String getSFilePath() ;'K5J9k
{ TdMruSY
return sFilePath; *fxG?}YT
} WH}y"W
)&O %*@F
G` A4|+W"
public void setSFilePath(String value) zw[m9N5\h
{ AT3Mlz~7#
sFilePath = value; tNI^@xdim1
} 8nJpp
dn3y\
m(!FHPvN
public String getSFileName() Fxz"DZY6
{ xp{tw$
return sFileName; [q-h|m
} eym4=k ~
"8MF_Gu):
7$=InK
public void setSFileName(String value) 0S~rgq|O
{ niyV8v
sFileName = value; tWRC$
} 9A=,E&
RrB&\9=
b$joY*< 6
public int getNSplitter() >bW#Zs,6
{ `^&OF uee
return nSplitter; eauF~md,
} Q &JUt(
KRzAy)8
Yq KCeg
public void setNSplitter(int nCount) %u'ukcL7
{ 6&x@.1('z
nSplitter = nCount; 0,")C5j
} ZE}}W_
} :I#V.
&QgR*,5eo
SJ,v?=S!
/* } Kgy
**Utility.java l_p2Riv
*/ ,J@
package NetFox; S1_RjMbYM
#6=
V,njO{Q
public class Utility { ]=BB#
=^?/+p8k
4pvMd
public Utility() hgq;`_;1,
{ ZECfR>`x
e^voW"?%
hVY$;s
} k_#)Tw*
|BXg/gW
//线程睡眠 |6-nbj
public static void sleep(int nSecond) 2>%=U~5
{ HRA|q
try{ x%B%f`]8
Thread.sleep(nSecond); GbI/4<)l}
} 59u}W 0
catch(Exception e) l/5 hp.
{ [/r(__.
e.printStackTrace (); ob]w;"
} XCQs2CHt
} h*\%vr
RA 6w}:sq7
//日志 9(Xn>G'iT
public static void log(String sMsg) Di{de`
{ wCBplaojJ
System.err.println(sMsg); :ws<-Qy
} At;LO9T3z
h?U O&(
"{t$nVJ
public static void log(int sMsg) *;FdD{+
{ }GM'.yutX
System.err.println(sMsg); (ZlU^Gw#UB
} z1a7*)8P
} -9?]IIVb
QT}tvm@PMq
<P<z N~i9j
/* .%-8 t{dt
**TestMethod.java c+ie8Q!
*/ 2\$oV
package NetFox; BgT*icd8d
c71y'hnT
!4!~Lk=
public class TestMethod { bN.Pex
DY*N|OnqJ
EU#^7
public TestMethod() |7~<Is~*
{ ///xx/weblogic60b2_win.exe >$7B wO
try{ zH r_!~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p#tI;"\y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P+}h$_x
SiteFileFetch fileFetch = new SiteFileFetch(bean); j~MI<I+l[
fileFetch.start(); WIGi51yC.x
} 0g;|y4SN=
catch(Exception e){e.printStackTrace ();} Z_NCD`i;
=_^X3z0
a+QpM*n7Lq
} Ny#^&-K
Gc7=
`]aeI'[}R
public static void main(String[] args) t{>q|0
{ wd6owr
new TestMethod(); <UCl@5g&
} ,!9zrYi}
} O6Y0XL
点击下载更多相关资料